OFFSET
1,2
COMMENTS
Logarithmic derivative of A179306.
MATHEMATICA
a[n_] := DivisorSum[n, Binomial[n, #] * DivisorSigma[1, #] * DivisorSigma[1, n/#] &]; Array[a, 35] (* Amiram Eldar, Aug 18 2023 *)
PROG
(PARI) {a(n)=sumdiv(n, d, binomial(n, d)*sigma(d)*sigma(n/d))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 10 2010
EXTENSIONS
a(33)-a(35) from Amiram Eldar, Aug 18 2023
STATUS
approved