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 A363888 #11 Jun 26 2023 06:33:45
%S A363888 0,0,1,0,0,0,2,0,0,0,2,0,0,0,2,0,0,1,2,0,0,0,2,0,0,0,2,0,2,0,2,0,0,0,
%T A363888 2,0,0,0,2,2,0,0,2,0,0,0,3,0,0,0,4,0,0,0,2,0,0,0,2,0,0,2,2,0,2,0,2,0,
%U A363888 0,0,2,0,2,0,2,0,0,0,2,0,0,0,4,2,0,0,2,0,0,1,2,0,0,0,4,0,0,0,2,0
%N A363888 Number of divisors of 7*n-5 of form 7*k+4.
%F A363888 a(n) = A363806(7*n-5).
%F A363888 G.f.: Sum_{k>0} x^(4*k-1)/(1 - x^(7*k-3)).
%t A363888 a[n_] := DivisorSum[7*n - 5, 1 &, Mod[#, 7] == 4 &]; Array[a, 100] (* _Amiram Eldar_, Jun 26 2023 *)
%o A363888 (PARI) a(n) = sumdiv(7*n-5, d, d%7==4);
%Y A363888 Cf. A363852, A363857, A363887.
%Y A363888 Cf. A363806.
%K A363888 nonn
%O A363888 1,7
%A A363888 _Seiichi Manyama_, Jun 26 2023