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 A363851 #15 Jun 25 2023 09:43:47
%S A363851 1,1,1,2,1,1,2,1,1,2,1,2,2,1,1,2,1,1,2,2,1,3,1,1,2,1,1,3,1,1,2,2,1,2,
%T A363851 1,2,3,1,1,2,1,2,2,2,1,2,1,1,2,1,1,5,1,2,2,1,1,2,1,2,2,2,1,2,1,1,3,2,
%U A363851 1,2,2,2,2,1,1,4,1,1,2,1,1,4,1,2,2,1,1,3,1,1,2,3,1,2,1,1,3,2,1,4
%N A363851 Number of divisors of 7*n-4 of form 7*k+1.
%C A363851 Also number of divisors of 7*n-4 of form 7*k+3.
%F A363851 a(n) = A279061(7*n-4) = A363805(7*n-4).
%F A363851 G.f.: Sum_{k>0} x^(3*k-2)/(1 - x^(7*k-6)).
%F A363851 G.f.: Sum_{k>0} x^k/(1 - x^(7*k-4)).
%t A363851 a[n_] := DivisorSum[7*n - 4, 1 &, Mod[#, 7] == 1 &]; Array[a, 100] (* _Amiram Eldar_, Jun 25 2023 *)
%o A363851 (PARI) a(n) = sumdiv(7*n-4, d, d%7==1);
%Y A363851 Cf. A279061, A363805.
%K A363851 nonn
%O A363851 1,4
%A A363851 _Seiichi Manyama_, Jun 24 2023