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A261142 - OEIS
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <html> <head> <link rel="stylesheet" href="/styles.css"> <meta name="format-detection" content="telephone=no"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <meta name=viewport content="width=device-width, initial-scale=1"> <meta name="keywords" content="OEIS,integer sequences,Sloane" /> <title>A261142 - OEIS</title> <link rel="search" type="application/opensearchdescription+xml" title="OEIS" href="/oeis.xml"> <script> var myURL = "\/A261142" function redir() { var host = document.location.hostname; if(host != "oeis.org" && host != "127.0.0.1" && !/^([0-9.]+)$/.test(host) && host != "localhost" && host != "localhost.localdomain") { document.location = "https"+":"+"//"+"oeis"+".org/" + myURL; } } function sf() { if(document.location.pathname == "/" && document.f) document.f.q.focus(); } </script> </head> <body bgcolor=#ffffff onload="redir();sf()"> <div class=loginbar> <div class=login> <a href="/login?redirect=%2fA261142">login</a> </div> </div> <div class=center><div class=top> <center> <div class=donors> The OEIS is supported by <a href="http://oeisf.org/#DONATE">the many generous donors to the OEIS Foundation</a>. </div> <div class=banner> <a href="/"><img class=banner border="0" width="600" src="/banner2021.jpg" alt="A261142 - OEIS"></a> </div> <div class="motdbox"> <div class="motd"> <p>Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).</p> </div> <div class="donate"> <div id="donate-button-container"> <div id="donate-button"></div> <script src="https://www.paypalobjects.com/donate/sdk/donate-sdk.js" charset="UTF-8"></script> <script> PayPal.Donation.Button({ env:'production', hosted_button_id:'SVPGSDDCJ734A', image: { src:'https://www.paypalobjects.com/en_US/i/btn/btn_donateCC_LG.gif', alt:'Donate with PayPal button', title:'PayPal - The safer, easier way to pay online!', } }).render('#donate-button'); </script> </div> <a href="https://oeisf.org/donate/"> <strong>Other ways to Give</strong> </a> </div> </div> </center> </div></div> <div class=center><div class=pagebody> <div class=searchbarcenter> <form name=f action="/search" method="GET"> <div class=searchbargreet> <div class=searchbar> <div class=searchq> <input class=searchbox maxLength=1024 name=q value="" title="Search Query"> </div> <div class=searchsubmit> <input type=submit value="Search" name=go> </div> <div class=hints> <span class=hints><a href="/hints.html">Hints</a></span> </div> </div> <div class=searchgreet> (Greetings from <a href="/welcome">The On-Line Encyclopedia of Integer Sequences</a>!) </div> </div> </form> </div> <div class=sequence> <div class=space1></div> <div class=line></div> <div class=seqhead> <div class=seqnumname> <div class=seqnum> A261142 </div> <div class=seqname> Numbers n such that n, p=prime(n) and q=prime(p) have the same sum of digits. </div> </div> <div class=scorerefs> 0 </div> </div> <div> <div class=seqdatabox> <div class=seqdata>88, 248, 826, 1417, 1571, 1595, 3682, 3928, 4448, 5089, 5137, 6479, 7754, 8038, 8384, 8461, 9257, 9640, 10393, 10825, 10922, 11878, 13294, 14290, 14767, 14941, 15977, 16786, 17684, 17777, 17935, 18437, 18677, 19495, 20497, 20555, 21649, 22487, 23239, 23396</div> <div class=seqdatalinks> (<a href="/A261142/list">list</a>; <a href="/A261142/graph">graph</a>; <a href="/search?q=A261142+-id:A261142">refs</a>; <a href="/A261142/listen">listen</a>; <a href="/history?seq=A261142">history</a>; <a href="/search?q=id:A261142&fmt=text">text</a>; <a href="/A261142/internal">internal format</a>) </div> </div> </div> <div class=entry> <div class=section> <div class=sectname>OFFSET</div> <div class=sectbody> <div class=sectline>1,1</div> </div> </div> <div class=section> <div class=sectname>COMMENTS</div> <div class=sectbody> <div class=sectline>Hence both p and q are Honaker primes (<a href="/A033548" title="Honaker primes: primes P(k) such that sum of digits of P(k) equals sum of digits of k.">A033548</a>) and both n and p are terms in <a href="/A033549" title="Numbers k such that sum of digits of k-th prime equals sum of digits of k.">A033549</a>.</div> </div> </div> <div class=section> <div class=sectname>LINKS</div> <div class=sectbody> <div class=sectline><a href="/A261142/b261142.txt">Table of n, a(n) for n=1..40.</a></div> </div> </div> <div class=section> <div class=sectname>EXAMPLE</div> <div class=sectbody> <div class=sectline>n=88, p=prime(n)=457 and q=prime(p)=3229 have the same sum of digits=16;</div> <div class=sectline>n=248, p=prime(n)=1571 and q=prime(p)=13217 have the same sum of digits=14;</div> <div class=sectline>n=660349, p=178115131 and q=178115131 have the same sum of digits=28.</div> </div> </div> <div class=section> <div class=sectname>CROSSREFS</div> <div class=sectbody> <div class=sectline>Cf. <a href="/A000040" title="The prime numbers.">A000040</a>, <a href="/A000720" title="pi(n), the number of primes <= n. Sometimes called PrimePi(n) to distinguish it from the number 3.14159...">A000720</a>, <a href="/A007953" title="Digital sum (i.e., sum of digits) of n; also called digsum(n).">A007953</a>, <a href="/A033548" title="Honaker primes: primes P(k) such that sum of digits of P(k) equals sum of digits of k.">A033548</a>, <a href="/A033549" title="Numbers k such that sum of digits of k-th prime equals sum of digits of k.">A033549</a>.</div> <div class=sectline>Sequence in context: <a href="/A116448" title="Orbital periods (length of year) of planets in the solar system, to the nearest whole number of terrestrial days.">A116448</a> <a href="/A046330" title="Palindromes with exactly 4 prime factors (counted with multiplicity).">A046330</a> <a href="/A304519" title="a(n) = 72*2^n -56 (n>=1).">A304519</a> * <a href="/A328872" title="Number of semi-magic (only short lines are magic) knight's tours on a 6 X n board.">A328872</a> <a href="/A001347" title="a(n) = Sum_{k=0..5} (n+k)! * C(5,k).">A001347</a> <a href="/A003782" title="Coefficients of Jacobi Eisenstein series of index 1 and weight 6.">A003782</a></div> <div class=sectline>Adjacent sequences: <a href="/A261139" title="S'_t(n) is the number of set partitions of {1,2,...,t} into exactly n parts such that no part contains both 1 and t or both ...">A261139</a> <a href="/A261140" title="a(n) = 3486107472997423 + (n-1)*371891575525470.">A261140</a> <a href="/A261141" title="Positive integers n that can be expressed as a product of Jacobsthal numbers (A001045), not necessarily distinct.">A261141</a> * <a href="/A261143" title="a(n) = H_n(1,2) where H_n is the n-th hyperoperator.">A261143</a> <a href="/A261144" title="Irregular triangle of numbers that are squarefree and smooth (row n contains squarefree p-smooth numbers, where p is the n-t...">A261144</a> <a href="/A261145" title="Numbers n such that n!3 + 3^10 is prime, where n!3 = n!!! is a triple factorial number (A007661).">A261145</a></div> </div> </div> <div class=section> <div class=sectname>KEYWORD</div> <div class=sectbody> <div class=sectline><span title="a sequence of nonnegative numbers">nonn</span>,<span title="dependent on base used for sequence">base</span></div> </div> </div> <div class=section> <div class=sectname>AUTHOR</div> <div class=sectbody> <div class=sectline><a href="/wiki/User:Zak_Seidov">Zak Seidov</a>, Oct 22 2015</div> </div> </div> <div class=section> <div class=sectname>STATUS</div> <div class=sectbody> <div class=sectline>approved</div> </div> </div> </div> <div class=space10></div> </div> </div></div> <p> <div class=footerpad></div> <div class=footer> <center> <div class=bottom> <div class=linksbar> <a href="/">Lookup</a> <a href="/wiki/Welcome"><font color="red">Welcome</font></a> <a href="/wiki/Main_Page"><font color="red">Wiki</font></a> <a href="/wiki/Special:RequestAccount">Register</a> <a href="/play.html">Music</a> <a href="/plot2.html">Plot 2</a> <a href="/demo1.html">Demos</a> <a href="/wiki/Index_to_OEIS">Index</a> <a href="/webcam">WebCam</a> <a href="/Submit.html">Contribute</a> <a href="/eishelp2.html">Format</a> <a href="/wiki/Style_Sheet">Style Sheet</a> <a href="/transforms.html">Transforms</a> <a href="/ol.html">Superseeker</a> <a href="/recent">Recents</a> </div> <div class=linksbar> <a href="/community.html">The OEIS Community</a> </div> <div class=linksbar> Maintained by <a href="http://oeisf.org">The OEIS Foundation Inc.</a> </div> <div class=dbinfo>Last modified December 3 15:56 EST 2024. Contains 378391 sequences.</div> <div class=legal> <a href="/wiki/Legal_Documents">License Agreements, Terms of Use, Privacy Policy</a> </div> </div> </center> </div> </body> </html>