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 A368612 #9 Jan 01 2024 22:28:32
%S A368612 0,0,1,4,8,13,20,27,37,46,56,65,81,92,107,122,140,153,175,190,214,234,
%T A368612 254,271,304,324,347,370,399,418,454,475,509,536,564,591,635,658,689,
%U A368612 719,763,788,835,862,904,945,981,1010,1070,1103,1148,1185,1231,1262,1318,1356
%N A368612 a(n) = Sum_{k=2..n} pi(k-1) * ceiling(n/k).
%F A368612 a(n) = A368610(n) - A092494(n).
%t A368612 Table[Sum[PrimePi[k - 1] Ceiling[n/k], {k, 2, n}], {n, 100}]
%Y A368612 Cf. A000720 (pi), A046992, A092494, A368610, A368611, A368613.
%K A368612 nonn,easy
%O A368612 1,4
%A A368612 _Wesley Ivan Hurt_, Dec 31 2023