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A365648
Dirichlet convolution of sigma with reduced totient function.
2
1, 4, 6, 12, 10, 24, 14, 30, 27, 40, 22, 70, 26, 56, 56, 70, 34, 108, 38, 116, 78, 88, 46, 172, 75, 104, 108, 162, 58, 224, 62, 158, 122, 136, 128, 310, 74, 152, 144, 284, 82, 312, 86, 254, 242, 184, 94, 396, 147, 300, 188, 300, 106, 432, 200, 396, 210, 232, 118
OFFSET
1,2
FORMULA
a(n) = Sum{d|n} A000203(d) * A002322(n/d).
a(p) = A365647(p) where p is a term of A000040.
MATHEMATICA
Table[DirichletConvolve[DivisorSigma[1, k], CarmichaelLambda[k], k, n], {n, 1, 100}] (* Amiram Eldar, Sep 15 2023 *)
PROG
(Python)
from sympy import divisors, reduced_totient, divisor_sigma
def a(n): return sum(divisor_sigma(d, 1) * reduced_totient(n//d) for d in divisors(n))
CROSSREFS
KEYWORD
nonn
AUTHOR
Torlach Rush, Sep 14 2023
STATUS
approved