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 A386594 #6 Jul 27 2025 11:28:33
%S A386594 1,3,4,6,5,12,7,12,12,15,11,25,13,22,21,24,17,36,19,30,28,33,23,50,25,
%T A386594 39,36,44,29,63,31,48,44,51,36,75,37,57,52,60,41,88,43,66,63,69,47,
%U A386594 100,49,75,68,78,53,108,55,89,76,87,59,131,61,93,84,96,65,132,67,102,92,113,71,150,73,111,105,114,77,157,79,120,108,123,83,183,85,129,116
%N A386594 a(n) = Sum_{d|n} d * c(n/d), where c = A351114.
%C A386594 Dirichlet convolution of n and c(n), where c = A351114.
%C A386594 For each divisor d of n, add n/d if phi(d) | sigma(d), else add 0.
%t A386594 Table[Sum[d*(1 - Ceiling[DivisorSigma[1, n/d]/EulerPhi[n/d]] + Floor[DivisorSigma[1, n/d]/EulerPhi[n/d]]), {d, Divisors[n]}], {n, 100}]
%Y A386594 Cf. A020492 (balanced numbers), A351114.
%K A386594 nonn
%O A386594 1,2
%A A386594 _Wesley Ivan Hurt_, Jul 26 2025