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 A245318 #28 Aug 16 2021 03:23:54 %S A245318 1,7,133,1517,11761,676333,1484413,3627557,10289371,1449045241, %T A245318 2433687407,12309023183,29013950411,11701492535299,223598572318157, %U A245318 362232879754103 %N A245318 Numbers k that divide 2^k + 5. %C A245318 No other terms below 10^15. Some large terms: 37367159696063084325121, 1637537600494693555095121, 50692913747901869910332539, 407*(2^407+5)/1125038874668278099 (108 digits). - _Max Alekseyev_, Sep 22 2016 %H A245318 OEIS Wiki, <a href="/wiki/2^n mod n">2^n mod n</a> %e A245318 2^7 + 5 = 133 is divisible by 7. Thus 7 is a term of this sequence. %t A245318 Select[Range[10^5], Divisible[2^# + 5, #] &] (* _Robert Price_, Oct 12 2018 *) %o A245318 (PARI) %o A245318 for(n=1,10^9,if(Mod(2,n)^n==Mod(-5,n),print1(n,", "))) %Y A245318 Cf. A128121, A168614. %K A245318 nonn,more %O A245318 1,2 %A A245318 _Derek Orr_, Jul 17 2014 %E A245318 a(10)-a(13) from _Lars Blomberg_, Nov 05 2014 %E A245318 a(14)-a(16) from _Max Alekseyev_, Oct 09 2016