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 A033871 #15 Jan 07 2023 11:44:05
%S A033871 3,7,11,19,39,63,91,99,143,147,171,183,231,247,363,399,427,507,539,
%T A033871 627,671,819,847,931,1083,1159,1183,1287,1463,1859,1911,2223,2299,
%U A033871 2379,2527,3003,3211,3843,3971,4719,4851,5187,5551,6039
%N A033871 Divisors = 3 (mod 4) of Descartes's 198585576189.
%C A033871 The number 198585576189 (which is the only known odd spoof-perfect number, cf. A174292) has 486 divisors, 240 of which are congruent to 3 modulo 4. - _M. F. Hasler_, Feb 17 2017
%H A033871 M. F. Hasler, <a href="/A033871/b033871.txt">Table of n, a(n) for n = 1..240</a>
%e A033871 198585576189 = 3^2 * 7^2 * 11^2 * 13^2 * 19^2 * 61.
%t A033871 Select[Divisors[198585576189],Mod[#,4]==3&] (* _Harvey P. Dale_, Jan 07 2023 *)
%o A033871 (PARI) lista() = {fordiv(198585576189, d, if (d % 4 == 3, print1(d, ", ")));} \\ _Michel Marcus_, Jul 14 2013
%o A033871 (PARI) select(d->d%4==1, divisors(198585576189)) \\ _M. F. Hasler_, Feb 17 2017
%Y A033871 Cf. A033870, A222262.
%K A033871 easy,fini,nonn,full
%O A033871 1,1
%A A033871 _Naohiro Nomoto_
%E A033871 Corrected by _Michel Marcus_, Jul 14 2013