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 A351688 #25 May 08 2022 08:23:08
%S A351688 3,17,23,37,67,89,193,227,257,593,641,769,1889,10331,12289,13441,
%T A351688 18433,40961,65537,85121,96769,2752513,3655681
%N A351688 Prime numbers p such that the order of the (p-1)-th Bell number B(p-1) is a power of 2 modulo p.
%C A351688 An odd prime p is a counterexample of Kurepa's conjecture if and only if B(p-1) = 1 modulo p.
%e A351688 a(1)=3 since B(2)=2 has order 2 modulo 3.
%e A351688 a(3)=37, since B(36)=6 modulo 37 has order 4 = 2^2 modulo 37.
%t A351688 Do[p = Prime[k]; m = Mod[BellB[p-1], p]; If[m != 0, f = FactorInteger[MultiplicativeOrder[m, p]]; If[Length[f] == 1 && f[[1, 1]] == 2, Print[p]]], {k, 1, 500}] (* _Vaclav Kotesovec_, May 06 2022 *)
%Y A351688 Cf. A000110.
%K A351688 nonn,more
%O A351688 1,1
%A A351688 _Luis H. Gallardo_, May 05 2022