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 A284363 #19 Apr 12 2024 04:36:13
%S A284363 1,1,1,1,1,7,8,9,1,1,1,7,14,22,16,9,1,7,1,21,29,23,1,15,1,14,28,50,30,
%T A284363 22,1,9,1,35,43,43,1,1,14,29,42,91,44,23,16,1,1,63,57,51,1,14,1,34,56,
%U A284363 114,58,30,1,42,1,63,92,73,14,29,1,35,70,127,72,51,1,1
%N A284363 a(n) = Sum_{d|n, d = 0, 1, or 6 mod 7} d.
%H A284363 Seiichi Manyama, <a href="/A284363/b284363.txt">Table of n, a(n) for n = 1..10000</a>
%F A284363 Sum_{k=1..n} a(k) ~ c * n^2, where c = Pi^2/28 = 0.352485... . - _Amiram Eldar_, Apr 12 2024
%t A284363 Table[Sum[If[Mod[d, 7] <2 || Mod[d, 7]==6, d, 0], {d, Divisors[n]}], {n, 80}] (* _Indranil Ghosh_, Mar 25 2017 *)
%o A284363 (PARI) a(n) = sumdiv(n, d, ((d + 1) % 7 < 3) * d); \\ _Amiram Eldar_, Apr 12 2024
%Y A284363 Cf. A232714.
%Y A284363 Cf. Sum_{d|n, d = 0, 1, or k-1 mod k} d: A000203 (k=3), A284361 (k=5), A284362 (k=6), this sequence (k=7), A284372 (k=12).
%K A284363 nonn
%O A284363 1,6
%A A284363 _Seiichi Manyama_, Mar 25 2017