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 A291360 #14 Sep 08 2022 08:46:19
%S A291360 3,5,7,11,13,17,19,31,37,41,61,73,97,109,151,181,241,257,331,433,577,
%T A291360 631,673,1321,23311,38737,54001,61681,8369281,18837001,29247661,
%U A291360 394783681,4278255361,4562284561,46908728641,168692292721,487824887233,469775495062434961,750016890283777055704738227247474485366338380663681
%N A291360 Prime divisors of 2^720 - 1.
%C A291360 It is possible to find an odd positive integer k and a set S = {p(1), ..., p(s)} containing only primes which appeared in the sequence such that for any nonnegative integer n, k*2^n + 1 == 0 (mod p(i)) and k*2^n - 1 == 0 (mod p(j)) for some p(i) and some p(j) from the set S.
%H A291360 <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>
%t A291360 Select[Divisors[2^720-1], PrimeQ]
%o A291360 (Magma) PrimeDivisors(2^720-1);
%o A291360 (PARI) forprime(p=1, , if(Mod(2, p)^720==1, print1(p, ", "))) \\ _Felix Fröhlich_, Aug 23 2017
%Y A291360 Cf. A076335, A154700. Supersequence of A269326.
%K A291360 nonn,easy,fini,full
%O A291360 1,1
%A A291360 _Arkadiusz Wesolowski_, Aug 23 2017