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 A364388 #6 Jul 23 2023 13:42:31
%S A364388 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A364388 1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,
%U A364388 1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1
%N A364388 Number of divisors of n of the form 5*k+1 that are at most sqrt(n).
%F A364388 G.f.: Sum_{k>=0} x^(5*k+1)^2 / (1 - x^(5*k+1)).
%t A364388 Table[Count[Divisors[n], _?(# <= Sqrt[n] && MemberQ[{1}, Mod[#, 5]] &)], {n, 100}]
%t A364388 nmax = 100; CoefficientList[Series[Sum[x^(5 k + 1)^2/(1 - x^(5 k + 1)), {k, 0, nmax}], {x, 0, nmax}], x] // Rest
%Y A364388 Cf. A001876, A038548, A364389.
%K A364388 nonn
%O A364388 1,36
%A A364388 _Ilya Gutkovskiy_, Jul 21 2023