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 A239564 #26 Feb 16 2025 08:33:21 %S A239564 154,504,5758,19912,245714,11251030,40679232,1967728552,26525975822, %T A239564 97753187576,1335948880418,68398141417510,3547322151373882, %U A239564 13260715720748120,697034813138756392,9825603574709578482,36935066391752894480,1970457739485406707872 %N A239564 a(n) = (round(c^prime(n)) - 1)/prime(n), where c is the pentanacci constant (A103814). %C A239564 For n>=5, round(c^prime(n)) == 1 (mod 2*prime(n)). Proof in Shevelev link. In particular, all terms are even. %H A239564 S. Litsyn and Vladimir 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 A239564 Vladimir 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 A239564 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PentanacciConstant.html">Pentanacci Constant</a> %Y A239564 Cf. A000040, A007619, A007663, A238693, A238697, A238698, A238700, A103814, A239502, A239544. %K A239564 nonn %O A239564 5,1 %A A239564 _Vladimir Shevelev_ and _Peter J. C. Moses_, Mar 21 2014