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 A365648 #12 Sep 20 2023 15:59:47
%S A365648 1,4,6,12,10,24,14,30,27,40,22,70,26,56,56,70,34,108,38,116,78,88,46,
%T A365648 172,75,104,108,162,58,224,62,158,122,136,128,310,74,152,144,284,82,
%U A365648 312,86,254,242,184,94,396,147,300,188,300,106,432,200,396,210,232,118
%N A365648 Dirichlet convolution of sigma with reduced totient function.
%F A365648 a(n) = Sum{d|n} A000203(d) * A002322(n/d).
%F A365648 a(p) = A365647(p) where p is a term of A000040.
%t A365648 Table[DirichletConvolve[DivisorSigma[1, k], CarmichaelLambda[k], k, n], {n, 1, 100}] (* _Amiram Eldar_, Sep 15 2023 *)
%o A365648 (Python)
%o A365648 from sympy import divisors, reduced_totient, divisor_sigma
%o A365648 def a(n): return sum(divisor_sigma(d, 1) * reduced_totient(n//d) for d in divisors(n))
%Y A365648 Cf. A000040, A000203, A002322, A365647.
%K A365648 nonn
%O A365648 1,2
%A A365648 _Torlach Rush_, Sep 14 2023