OFFSET
1,2
MATHEMATICA
psi[n_Integer] := n * Times @@ (1 + 1/FactorInteger[n][[;; , 1]]); psi[1] = 1; Table[DirichletConvolve[psi[k], CarmichaelLambda[k], k, n], {n, 1, 100}] (* Amiram Eldar, Sep 15 2023 *)
PROG
(Python)
from sympy import divisors, primefactors, prod, reduced_totient
def psi(n):
return n*prod(p+1 for p in primefactors(n))//prod(primefactors(n))
def a(n): return sum(psi(d) * reduced_totient(n//d) for d in divisors(n))
CROSSREFS
KEYWORD
nonn
AUTHOR
Torlach Rush, Sep 14 2023
STATUS
approved