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 A369747 #12 Jun 26 2024 21:49:29
%S A369747 0,0,0,1,0,3,0,2,2,4,0,5,0,5,5,4,0,7,0,6,6,6,0,9,3,7,4,8,0,13,0,6,7,8,
%T A369747 7,12,0,9,8,12,0,17,0,10,10,10,0,15,4,13,9,11,0,16,8,13,10,11,0,23,0,
%U A369747 12,12,11,9,22,0,13,11,21,0,20,0,13,15,14,9,24,0,18,9
%N A369747 a(n) = Sum_{p|n, p prime} pi(n/p).
%F A369747 a(p^k) = pi(p^(k-1)), for p prime and k >= 1. - _Wesley Ivan Hurt_, Jun 26 2024
%t A369747 Table[DivisorSum[n, PrimePi[n/#] &, PrimeQ[#] &], {n, 100}]
%Y A369747 Cf. A000040, A000720 (pi), A062774, A345301, A369745.
%K A369747 nonn,easy
%O A369747 1,6
%A A369747 _Wesley Ivan Hurt_, Jan 30 2024