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 A364107 #13 Jul 12 2023 01:01:21
%S A364107 0,0,0,1,0,0,0,3,0,0,0,4,0,0,0,5,2,0,0,6,0,0,0,7,0,5,0,8,0,0,0,9,0,0,
%T A364107 6,10,0,0,0,14,0,0,0,19,0,0,0,13,0,0,0,14,8,7,0,15,0,0,0,16,0,9,0,17,
%U A364107 0,0,0,26,0,0,10,19,4,0,0,20,0,0,0,32,0,9,0,22,0,0,0,23,12,0,0,33,0,0,0
%N A364107 Expansion of Sum_{k>0} k * x^(4*k) / (1 - x^(5*k-1)).
%F A364107 a(n) = (1/5) * Sum_{d | 5*n-4, d==4 (mod 5)} (d+1).
%F A364107 G.f.: Sum_{k>0} x^(4*k) / (1 - x^(5*k-1))^2.
%t A364107 a[n_] := DivisorSum[5*n - 4, # + 1 &, Mod[#, 5] == 4 &]/5; Array[a, 100] (* _Amiram Eldar_, Jul 12 2023 *)
%o A364107 (PARI) a(n) = sumdiv(5*n-4, d, (d%5==4)*(d+1))/5;
%Y A364107 Cf. A364104, A364105, A364106.
%Y A364107 Cf. A359241, A364103.
%K A364107 nonn
%O A364107 1,8
%A A364107 _Seiichi Manyama_, Jul 05 2023