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 A363803 #13 Jun 23 2023 10:32:05
%S A363803 0,2,0,2,5,2,7,2,9,7,0,14,0,23,5,18,0,11,19,7,28,2,23,14,5,28,9,51,0,
%T A363803 37,0,18,33,2,47,23,37,21,0,47,0,86,0,46,14,25,47,30,56,7,51,28,0,65,
%U A363803 5,107,19,60,0,49,61,2,100,18,70,35,0,70,23,133,0,95,0,39,80,21,84,28,79,63,9,84,0
%N A363803 a(n) = Sum_{d|n, d == 0, 2, or 5 mod 7} d.
%F A363803 G.f.: Sum_{k>0, k == 0, 2 or 5 mod 7} k * x^k/(1 - x^k).
%t A363803 a[n_] := DivisorSum[n, # &, MemberQ[{0, 2, 5}, Mod[#, 7]] &]; Array[a, 100] (* _Amiram Eldar_, Jun 23 2023 *)
%o A363803 (PARI) my(N=90, x='x+O('x^N)); concat(0, Vec(sum(k=1, N, [1, 0, 1, 0, 0, 1, 0][k%7+1]*k*x^k/(1-x^k))))
%Y A363803 Cf. A284363, A284443, A284446, A363804.
%Y A363803 Cf. A363800.
%K A363803 nonn,easy
%O A363803 1,2
%A A363803 _Seiichi Manyama_, Jun 23 2023