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 A359287 #18 Aug 16 2023 02:27:18
%S A359287 1,0,2,0,2,0,2,0,2,1,2,0,2,0,2,0,4,0,2,0,2,0,2,2,2,0,2,0,3,0,4,0,2,0,
%T A359287 2,0,2,2,2,0,4,0,2,0,4,0,2,0,2,0,2,2,4,0,2,0,2,1,4,0,2,0,2,0,4,2,2,0,
%U A359287 2,0,2,0,4,0,4,0,4,0,2,2,2,0,2,0,2,0,4,0,4,0
%N A359287 Number of divisors of 5*n-1 of form 5*k+2.
%H A359287 Seiichi Manyama, <a href="/A359287/b359287.txt">Table of n, a(n) for n = 1..10000</a>
%F A359287 a(n) = A001877(5*n-1).
%F A359287 G.f.: Sum_{k>0} x^(2*k-1)/(1 - x^(5*k-3)).
%t A359287 a[n_] := DivisorSum[5*n-1, 1 &, Mod[#, 5] == 2 &]; Array[a, 100] (* _Amiram Eldar_, Aug 16 2023 *)
%o A359287 (PARI) a(n) = sumdiv(5*n-1, d, d%5==2);
%o A359287 (PARI) my(N=100, x='x+O('x^N)); Vec(sum(k=1, N, x^(2*k-1)/(1-x^(5*k-3))))
%Y A359287 Cf. A001877.
%Y A359287 Cf. A359233, A359288.
%Y A359287 Cf. A359237, A359244, A359269.
%K A359287 nonn,easy
%O A359287 1,3
%A A359287 _Seiichi Manyama_, Dec 24 2022