This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A239544 #27 Feb 16 2025 08:33:21 %S A239544 14,124,390,4118,13690,156122,6351030,22074820,948652694,11818395344, %T A239544 41868809842,528803858638,24052859078262,1108257471317098, %U A239544 3982717894786008,185987895674303758,2422894681885464596,8755616404517667662,414985190213435939298 %N A239544 (Round(c^prime(n)) - 1)/prime(n), where c is the tetranacci constant (A086088). %C A239544 For n>=4, round(c^prime(n)) == 1 (mod 2*prime(n)). Proof in Shevelev link. In particular, all terms are even. %H A239544 S. Litsyn and V. Shevelev, <a href="http://dx.doi.org/10.1142/S1793042105000339">Irrational Factors Satisfying the Little Fermat Theorem</a>, International Journal of Number Theory, vol.1, no.4 (2005), 499-512. %H A239544 V. Shevelev, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2014-March/012750.html">A property of n-bonacci constant</a>, Seqfan (Mar 23 2014) %H A239544 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TetranacciConstant.html">Tetranacci Constant</a> %Y A239544 Cf. A007619, A007663, A238693, A238697, A238698, A238700, A086088, A239502. %K A239544 nonn %O A239544 4,1 %A A239544 _Vladimir Shevelev_ and _Peter J. C. Moses_, Mar 21 2014