A179305 - OEIS

A179305

a(n) = Sum_{d|n} C(n,d)*sigma(d).

1, 5, 7, 29, 11, 143, 15, 597, 358, 1675, 23, 15671, 27, 27767, 19877, 206197, 35, 858608, 39, 3453179, 935613, 8465935, 47, 88446975, 318836, 145609443, 60940492, 972415263, 59, 4271628733, 63, 18791519893, 2322462545, 42004913731, 55744035

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OFFSET

1,2

COMMENTS

Logarithmic derivative of A179304.

LINKS

Table of n, a(n) for n=1..35.

MATHEMATICA

a[n_] := DivisorSum[n, Binomial[n, #] * DivisorSigma[1, #] &]; Array[a, 35] (* Amiram Eldar, Aug 18 2023 *)

PROG

(PARI) a(n)=sumdiv(n, d, sigma(d)*binomial(n, d))

CROSSREFS

Cf. A000203, A179304.

Sequence in context: A126888 A358582 A185302 * A307100 A229337 A227857

Adjacent sequences: A179302 A179303 A179304 * A179306 A179307 A179308

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jul 10 2010

STATUS

approved