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 A363028 #19 Jul 07 2023 06:38:18
%S A363028 1,0,3,0,4,0,5,0,6,2,7,0,8,0,9,0,15,0,11,0,12,0,13,6,14,0,15,0,19,0,
%T A363028 24,0,18,0,19,0,20,8,21,0,29,0,23,0,33,0,25,0,26,0,27,10,36,0,29,0,30,
%U A363028 4,42,0,32,0,33,0,43,12,35,0,36,0,37,0,51,0,48,0,50,0,41,14,42,0,43,0,44,0,60,0
%N A363028 Expansion of Sum_{k>0} k * x^(2*k-1) / (1 - x^(5*k-3)).
%H A363028 Seiichi Manyama, <a href="/A363028/b363028.txt">Table of n, a(n) for n = 1..10000</a>
%F A363028 a(n) = (1/5) * Sum_{d | 5*n-1, d==2 (mod 5)} (d+3).
%F A363028 G.f.: Sum_{k>0} x^(2*k-1) / (1 - x^(5*k-3))^2.
%t A363028 a[n_] := DivisorSum[5*n - 1, # + 3 &, Mod[#, 5] == 2 &]/5; Array[a, 100] (* _Amiram Eldar_, Jul 06 2023 *)
%o A363028 (PARI) a(n) = sumdiv(5*n-1, d, (d%5==2)*(d+3))/5;
%Y A363028 Cf. A359287, A362952.
%Y A363028 Cf. A363155, A364096, A364104.
%K A363028 nonn
%O A363028 1,3
%A A363028 _Seiichi Manyama_, Jul 06 2023