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 A331741 #24 Dec 20 2024 02:08:53
%S A331741 16,144,400,784,1936,2704,3600,4624,5776,7056,8464,10000,13456,15376,
%T A331741 17424,19600,21904,24336,26896,29584,35344,38416,41616,44944,48400,
%U A331741 51984,55696,59536,67600,71824,76176,80656,85264,90000,94864,99856,104976,110224,115600,121104,126736,132496,138384,144400,150544,163216,169744,176400
%N A331741 Squares s such that A331733(s) = sigma(A225546(n)) is congruent to 2 modulo 4.
%C A331741 Squares s for which A331733(s) is two times an odd number, i.e., squares s such that A007814(A331733(s)) == 1.
%C A331741 For each term k present, A006519(k) = 2^(2^e), with A000040(1+e) == 1 (mod 4). See A191218, A228058.
%C A331741 Equal to the sequence A225546(A191218(n)), for n >= 1, when its elements are sorted into ascending order.
%F A331741 {n: A010052(n)*A007814(A331733(n)) == 1}.
%t A331741 Select[Range[100]^2, Mod[DivisorSigma[1, If[# == 1, 1, Apply[Times, Flatten@ Map[Function[{p, e}, Map[Prime[Log2@# + 1]^(2^(PrimePi@ p - 1)) &, DeleteCases[NumberExpand[e, 2], 0]]] @@ # &, FactorInteger[#]]]]], 4] == 2 &] (* _Michael De Vlieger_, Feb 08 2020 *)
%o A331741 (PARI)
%o A331741 k=0; for(n=1,500,if(!(n%2)&&(1==A007814(A331733(n^2))),k++; write("b331741.txt", k, " ", n^2); print(n^2, " -> ", factor(n^2),", ")));
%Y A331741 Cf. A006519, A007814, A010052, A067403, A191218, A225546, A228058, A331733, A331734.
%K A331741 nonn
%O A331741 1,1
%A A331741 _Antti Karttunen_, Feb 03 2020