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 A127263 #25 May 01 2025 01:54:07
%S A127263 1,3,57,32547,9961491,297381939,1338104811,3942759027,5688011361,
%T A127263 8920514307,9146532873,40253706489,243640690617,764039295291,
%U A127263 1127102902923,1556475424971,2251315404417,3005607686883,5222670270483
%N A127263 Numbers k such that k^3 divides 2^(k^2)+1.
%C A127263 If k belongs to this sequence, then so does (2^(k^2)+1)/k^2.
%C A127263 From _Alexander Adamchuk_, May 14 2010: (Start)
%C A127263 3 divides a(n) for n>1.
%C A127263 19 divides a(n) for n>2. (End)
%H A127263 ArtOfProblemSolving forum, <a href="https://artofproblemsolving.com/community/c6h140435p796197">n^3 | (2^{n^2}+1)</a>
%t A127263 Select[Range[100000], Divisible[2^(#^2) + 1, #^3] &] (* _Robert Price_, Mar 23 2020 *)
%Y A127263 Cf. A006521, A093546, A093665, A136372, A128677.
%Y A127263 Cf. A128678, A128679, A128680, A128681, A128682, A128683, A128684, A128685, A177813, A177814, A177816, A177817, A177818, A177819, A177820.
%K A127263 nonn
%O A127263 1,2
%A A127263 _Max Alekseyev_, Mar 27 2007, Mar 29 2007, Apr 18 2007
%E A127263 a(7) from _Ryan Propper_, Jan 01 2008
%E A127263 a(8)-a(19) from _Max Alekseyev_, May 14 2010