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A027112 - 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>A027112 - OEIS</title> <link rel="search" type="application/opensearchdescription+xml" title="OEIS" href="/oeis.xml"> <script> var myURL = "\/A027112" 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=%2fA027112">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="A027112 - OEIS"></a> </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> A027112 </div> <div class=seqname> a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by <a href="/A027082" title="Irregular triangular array: T(n,0) = 1 for n >= 1; T(n,1) = T(n,2) = 1 for n >= 1; T(n,k) = T(n-1,k-3) + T(n-1,k-2) + T(n-1,...">A027082</a>. </div> </div> <div class=scorerefs> 0 </div> </div> <div> <div class=seqdatabox> <div class=seqdata>29, 238, 2012, 16975, 143106, 1207017, 10191450, 86181211, 730023605, 6195099626, 52668845006, 448581627313, 3827264611569, 32708905417122, 279989900778562, 2400407089060955, 20609200162062499, 177190108342853474, 1525420499563895994, 13148693465859069309</div> <div class=seqdatalinks> (<a href="/A027112/list">list</a>; <a href="/A027112/graph">graph</a>; <a href="/search?q=A027112+-id:A027112">refs</a>; <a href="/A027112/listen">listen</a>; <a href="/history?seq=A027112">history</a>; <a href="/search?q=id:A027112&fmt=text">text</a>; <a href="/A027112/internal">internal format</a>) </div> </div> </div> <div class=entry> <div class=section> <div class=sectname>OFFSET</div> <div class=sectbody> <div class=sectline>3,1</div> </div> </div> <div class=section> <div class=sectname>LINKS</div> <div class=sectbody> <div class=sectline><a href="/A027112/b027112.txt">Table of n, a(n) for n=3..22.</a></div> </div> </div> <div class=section> <div class=sectname>CROSSREFS</div> <div class=sectbody> <div class=sectline>Sequence in context: <a href="/A372962" title="a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} ( n/gcd(x_1, x_2, x_3, n) )^2.">A372962</a> <a href="/A091630" title="Numbers n + product of digits associated with A091628.">A091630</a> <a href="/A251424" title="Number of length n+2 0..4 arrays with the sum of the maximum minus twice the median plus the minimum of adjacent triples mul...">A251424</a> * <a href="/A142095" title="Primes congruent to 29 mod 35.">A142095</a> <a href="/A140845" title="Primes of the form 210k + 29.">A140845</a> <a href="/A223837" title="Number of n X 7 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing.">A223837</a></div> <div class=sectline>Adjacent sequences: <a href="/A027109" title="a(n) = Sum_{k=0..n} T(n,k) * T(n,n+k), with T given by A027082.">A027109</a> <a href="/A027110" title="a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A027082.">A027110</a> <a href="/A027111" title="a(n) = Sum_{k=0..2n-2} T(n,k) * T(n,k+2), with T given by A027082.">A027111</a> * <a href="/A027113" title="Triangular array T given by rows: T(n,0)=1 for n >= 0, T(n,1)=1,T(n,2)=2 for n >= 1 and for n >= 2, T(n,k)=T(n-1,k-3)+T(n-1,...">A027113</a> <a href="/A027114" title="a(n) = A027113(n, n+2).">A027114</a> <a href="/A027115" title="a(n) = T(n,0) + T(n,1) + ... + T(n,2n), T given by A027113.">A027115</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></div> </div> </div> <div class=section> <div class=sectname>AUTHOR</div> <div class=sectbody> <div class=sectline><a href="/wiki/User:Clark_Kimberling">Clark Kimberling</a></div> </div> </div> <div class=section> <div class=sectname>EXTENSIONS</div> <div class=sectbody> <div class=sectline>More terms from <a href="/wiki/User:Sean_A._Irvine">Sean A. Irvine</a>, Oct 23 2019</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 February 16 07:09 EST 2025. Contains 380893 sequences.</div> <div class=legal> <a href="/wiki/Legal_Documents">License Agreements, Terms of Use, Privacy Policy</a> </div> </div> </center> </div> </body> </html>