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 A306912 #9 Mar 17 2019 21:14:37
%S A306912 1,2,3,5,8,14,21,35,52,79,113,168,231,331,450,617,826,1122,1469,1958,
%T A306912 2540,3315,4260,5514,6995,8946,11280,14260,17840,22404,27790,34631,
%U A306912 42749,52834,64846,79708,97234,118870,144394,175476,212170,256752,309007,372267,446437,535368
%N A306912 a(n) = 1 + Sum_{k=1..n} Sum_{d|k} mu(k/d)*p(d), where p(d) = number of partitions of d (A000041).
%C A306912 Partial sums of A000837.
%F A306912 a(n) ~ exp(Pi*sqrt(2*n/3)) / (2^(3/2)*Pi*sqrt(n)). - _Vaclav Kotesovec_, Mar 17 2019
%t A306912 Table[1 + Sum[Sum[MoebiusMu[k/d] PartitionsP[d], {d, Divisors[k]}], {k, 1, n}], {n, 0, 45}]
%o A306912 (PARI) a(n) = 1 + sum(k=1, n, sumdiv(k, d, moebius(k/d)*numbpart(d))); \\ _Michel Marcus_, Mar 16 2019
%Y A306912 Cf. A000041, A000070, A000837, A008683, A036469.
%K A306912 nonn
%O A306912 0,2
%A A306912 _Ilya Gutkovskiy_, Mar 16 2019