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 A385313 #10 Jul 02 2025 12:15:31
%S A385313 1,2,3,6,5,8,7,16,15,14,11,30,13,20,23,40,17,45,19,54,33,32,23,80,45,
%T A385313 38,63,78,29,97,31,96,53,50,59,144,37,56,63,144,41,139,43,126,135,68,
%U A385313 47,200,91,135,83,150,53,189,95,208,93,86,59,300,61,92,195,224,113,223,67,198,113,245,71,372,73,110,225,222,137,265,79,360,243,122,83,432
%N A385313 a(n) = c(n) + Sum_{d|n} d * phi(n/d) * (1 - c(d)), where c = A010051.
%C A385313 Möbius transform of A380447.
%F A385313 a(n) = Sum_{d|n} A380447(d) * mu(n/d).
%F A385313 a(p^k) = (1-k+k*p)*p^(k-1) for p prime, k>=1. - _Wesley Ivan Hurt_, Jul 02 2025
%t A385313 Table[(PrimePi[n] - PrimePi[n - 1]) + Sum[d*EulerPhi[n/d] (1 - (PrimePi[d] - PrimePi[d - 1])), {d, Divisors[n]}], {n, 100}]
%Y A385313 Cf. A000010 (phi), A010051, A018804, A380447.
%K A385313 nonn
%O A385313 1,2
%A A385313 _Wesley Ivan Hurt_, Jun 25 2025