|
%I #19 Sep 08 2022 08:46:25
%S 1,3,5,8,9,15,13,18,21,27,21,38,25,39,41,40,33,63,37,68,59,63,45,84,
%T 65,75,81,98,57,123,61,88,95,99,105,156,73,111,113,150,81,177,85,158,
%U 165,135,93,184,133,195
%N Dirichlet convolution of the identity function with the reduced totient function.
%C This sequence differs from A018804 when A002322 differs from A000010.
%F a(n) = Sum_{d|n} d*A002322(n/d).
%t a[n_] := DivisorSum[n, # * CarmichaelLambda[n/#] &]; Array[a, 50] (* _Amiram Eldar_, Jan 13 2020 *)
%o (PARI) a(n) = sumdiv(n, d, d * lcm(znstar(n/d)[2])); \\ _Daniel Suteu_, Jan 13 2020
%o (Magma) [1] cat [&+[d*CarmichaelLambda(n div d):d in Set(Divisors(n)) diff {n}]+n:n in [2..60]]; // _Marius A. Burtea_, Jan 14 2020
%Y Cf. A000010 (phi), A002322 (psi), A018804 (Pillai's arithmetical function).
%K nonn
%O 1,2
%A _Torlach Rush_, Jan 13 2020
|
