CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "oeis.org",cType: 'managed',cRay: '92aaf144df9d5f93',cH: 'kU8RJ8kHkUl33tj6p5.0xFs3vhtswQr7RQeWOCywlxQ-1743708227-1.2.1.1-nF9cxZ.JeBw0JhvPrKM2C60gHMDqSN2QuufLEM.qWR2tNY1H7mjVlyKqhdEs2NjU',cUPMDTk: "\/A259396?__cf_chl_tk=LjtLg_NhTOLNDjMgCPZnVPOFQGC.26fnDnRE41voNqw-1743708227-1.0.1.1-s_6d7zvkjtHwIDM3cK_LqRMhHSDuTukUikBqhixNpt4",cFPWv: 'g',cITimeS: '1743708227',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/A259396?__cf_chl_f_tk=LjtLg_NhTOLNDjMgCPZnVPOFQGC.26fnDnRE41voNqw-1743708227-1.0.1.1-s_6d7zvkjtHwIDM3cK_LqRMhHSDuTukUikBqhixNpt4",md: "DWqGoO_sCsRiJ9AtA7xVJlzZfiEaeloi_e1JWuJyg6c-1743708227-1.2.1.1-kHSXwO8fqXzkh9_dYEevxPY4XoUAn8GEr0NCp0kzMg.XajN7d9MZ0kyZIeadYs9rUZ4_EI6MCNhR.Dh1t6QUgfXe8KgtukNfiJS.Z5xqqSubs8IskLzHBbg9l8e7SVw9ZXQcd4vR41HjuMjX3W.RED8CU3srJVoNbxzEPDKr2vSu2wbey9cok3aFi1iSHIUhb94bPp_ObC8zf0H73Zfp4rrdXbGYjxJzy4GOZhuMe1.dcfax1gen95WNNMtqkw18rPyFbBeOxxP7td.CWzDxICRcak3BsjmPHgmB8QEueEUUJPNyYpaigJA0pHgJyAGIcjzB5GV1D.OXwqxlouXl8ydvBJ7_G6WJTVEPjoXG8RZMVHqIgP665PbyUlHI7ZebaEqoVIQgBJcddDpyBvPpkb2qFOv4fubDgnLRLsfWje98SpsNYcUlMbIKbNB4g0aXBdMR3XWnjYXMrNr9ScfCs0MIh83niw1zrZWcDA4yDgA9Igs732HyWdrkTHL3BNwrQUQOGmYYHwojiD01.KVdQims8i9HdIxF5KSoM0VzaUsabIQNLb.RCTuKKBd5gkNCGa1I9A7ZQbjrycU7MihhMVv6OqjlerB9BtqEBead_R7hvuosd5BKfXzr8v7IrAVR5UpKL5xuUDj6SXT7rSLSgXOASF4c_iXJdnrvEQ6uS3ra1uNFs5yhj8nq08JQsQ6VlRyWAHS7dnKFh1TgrsJxNifJ2rCql3XQ2tLXsLGF51YC7fqYEcsRq5QS4BuQ4QaEEpiSNt6HfF0IrN22RNyafvnwmocts_Wsz9Gi_5T8ruT15shiN9TdjXKvXzac9GmTEIi21i3KZYpOdmcCMnUeI1MTnxgSOcPI8.Yjxrq81dPV3LeNfRqQL1sBmrfUfUAHPrZk.43HNa6gdr_1brGfsqd1OQM48nFx3urkl_.HwVGVfuLjGGaNc0hWBbtCZv0uIdVHZZWt4TLhvdCN_QqwLzisbLd9pIwqVg1KssAWme0Nfb9C_VcLcJE.D7o47sW7b68rH.rD.jlY0.HZ2aXtXxeGiLzsqzwlqkMXiPtemIiFmL_Q_v_UJAuhfAm3VBoO",mdrd: "0eJuvkCFbE6X3AXDu7CPyh2HMVtGUeNRSawRpUrtxN4-1743708227-1.2.1.1-Yvnjyw.RGgx6AB5RO3hWn9SCWKMkYnEmEvLtd8wVoYyT9ZYVcIQuo7fRxpNIIubkYVUJ1NNpbn9wdIgKwczRyulcCI_viZ51jB0QjAkKiSolXGLzyqeN.1uTjgLvWr6q2TGegchjHTQ7P2TfqK8hORnL2pHb6i3G0ENngeF0pHyz8pS06qa175pzSdijlNm0z3S9IsNk7EYtHKNNHBl2F7JufBfXdltmW.rRNOluNhuGciVo0_IG2X48.8.mNYlAE9KwwyzeQ3XPiVJol2MbEDoqYKRTGH.8mzoHIYYVT7rjMckEHM80n9hBFg8Dmuy0Yz9PduLBPZJe2eNuFVypRgMYRBNuP2iVINedr1G__o3oMxN7lhd8.ECs49faqW1anzt0qujhpg.HBrDwfGVzCdQ4dYdU6qAvguq0KMCKPe4dOhwylHH7Abbe7c_AFpi5.FGslHFzsCYYXXVSwl6pfPepp.QjsjXtAFm5xb4FiV3sclTW86J6PaN8EITM7Eo1ZhfGwOwqSzCfoIeAu2lX1IoLFIydI4isACtDzV7sE2jYArZBXAGfLwUvBdu1iYH02vkenwoF22XbIRj93L5b4YiIDd1GUYsIROb1YbdJT1.qf4LqsReuDP5eeYhMwHsYMU5A.iP.gWM76Rx7_PKSV4AwrWILxadouSDEMSCvSIEZTeTUOO4EEPplVw9J39gapoY_xVFJcUUt_kPIHBdJxn9NXkFFeDJpvANZRfbPGHaNwD4KvshLzK_dkK2N.dOnksZjO1wY.Hdf1N116jf0EW6C3aOkig_viYlM6FXQ7W8qVrMuH.0UAK58Fo_bAJ82rb2NxtvlZoIQ7N9Ch1Yn4vQ0mZ3t6wCSImKLfv8JaboSA3bas4JJYxzCWpZMNFYKAxI7g1StOBcmFDPDA.QN34DY8jQCE6KP5aBjSze1pF9vP9qhUxqipTspFoiSp3Alab9iOuD582Ws_dW9KGqrRsDdCU56A7szcc9V.l9GiEjc0GL763G7w3jjt4oZ2JL2UZSgeZIsRXoGYTSIT5Xou1_Xn7LZcWv2fMraMExBYaqRmkcll7nneBfY1hP8PChJ9aiDM5u_ArrNNd.CgvpDlPF6qLOb8B9QfamPCu1uW5hAxe1ZN0SK2cRUQTcTSajeODemtfMCcsYKRxVMDYV_e2zNiVqd6cqtEJHy4rHSScJ4zQV_dksQ9HrMgLKFgy2cNxG4ECcmUdKv1Iql5OwjsmfXYHGB8GBGt79WhL7GPFSwZioe1LJJAPNR5OYgj8u9BqDizmL4lSff3pMoIk83y1SmXKLtkHHO6RDBoSOWCJpDgwEOdVfs798GJKAi1DtZFg7D082cV5CAG1CpJ4l52vghDKPHB6rawus_aYifcEBq6QOMcTMraKCrh5xUN5CUlY45RosVcy4qA4KMo8_sstbw__eEPJyDmuNOKQlXWiybsSfP6JOnATwgWVr60VQcJwHfV7AnDiOcnQ4u9eeCJMFNO0uz2gbllV2QIRSQDXa.5Hju1kwddYCPJlV9HTlhI5DF5Dj5quj7i7ael17hu5nvE0q.D9pJBIRcN5MraZSYylVWc2z.iAosLGlsNeXVhW_Gq1UiQm4n7T2LdgulDmP3I3wkzMk1WUbYuK28AV.EUf0gnDszrUxOXdiFAf0NUHErVj5frW60lAiGdHlVUqkqNLNWQJCNLX6xL99B8q7ohNSFASwgURMJIpr2BJGqsHM7jnNaVrod85OUr0Em73qKEsHgjzmNUSd6LJtuOU6xdGBgD3e3h8XrX96szyhrkbD_mLky.9pGhBLhnXC40p0QVVe6WI2FSHrH_CTIc.hhF1oomR2_M0X2.HCgn6pU6DmdK6b4rYNtrb75HZXCzWEn38W2jYfO_Bt0l5Uh4Cl9Wjlk0.ZfRRtqAaKSz4hzHFcbp3JDIEHPAV8aCBu2vlQeD9rEyaVsCSLhdcTlfKkrb3L0MthAVLFbEBzIMkP1SWtFtmXMWL.HJCGqfZxnqoMbpqlKRUcFD7ZG3ELwV9GGABcvIQmxGt.Q36_cEsAqClFMJhd.rhcYrnKFOVHY_A"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92aaf144df9d5f93';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/A259396?__cf_chl_rt_tk=LjtLg_NhTOLNDjMgCPZnVPOFQGC.26fnDnRE41voNqw-1743708227-1.0.1.1-s_6d7zvkjtHwIDM3cK_LqRMhHSDuTukUikBqhixNpt4" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>