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 A363928 #14 Jun 30 2023 08:36:08
%S A363928 0,0,1,0,0,1,0,2,1,0,0,1,3,0,1,2,0,5,0,0,1,0,5,3,0,3,1,6,0,1,0,2,8,0,
%T A363928 0,5,0,8,4,2,0,1,9,0,1,5,0,13,0,0,1,3,11,5,0,8,1,12,0,1,0,0,14,2,3,8,
%U A363928 0,14,6,0,0,7,15,0,1,8,0,20,0,2,1,0,17,7,0,9,1,20,0,5,3,5,20,0,0,13,0,20,8,0,0
%N A363928 Expansion of Sum_{k>0} x^(3*k) / (1 - x^(5*k))^2.
%H A363928 Seiichi Manyama, <a href="/A363928/b363928.txt">Table of n, a(n) for n = 1..10000</a>
%F A363928 a(n) = (1/5) * Sum_{d|n, d==3 mod 5} (d+2) = (2 * A001878(n) + A284281(n))/5.
%F A363928 G.f.: Sum_{k>0} k * x^(5*k-2) / (1 - x^(5*k-2)).
%t A363928 a[n_] := DivisorSum[n, # + 2 &, Mod[#, 5] == 3 &] / 5; Array[a, 100] (* _Amiram Eldar_, Jun 28 2023 *)
%o A363928 (PARI) a(n) = sumdiv(n, d, (d%5==3)*(d+2))/5;
%Y A363928 Cf. A363925, A363926, A363929.
%Y A363928 Cf. A001878, A284281.
%K A363928 nonn
%O A363928 1,8
%A A363928 _Seiichi Manyama_, Jun 28 2023