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A262349 Sum of the divisors of the n-th Bell number. 0
1, 1, 3, 6, 24, 98, 240, 878, 13104, 34560, 143840, 1628640, 4421376, 27644438, 291751956, 1666163520, 10523628456, 216625138884, 779556556800, 5873176163328, 107021765366544, 633207380826720, 6399554302310400, 66975753492138600, 594616643557427040 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..24.

Eric Weisstein's World of Mathematics, BellNumber

Eric Weisstein's World of Mathematics, DivisorFunction

FORMULA

a(n) = sigma_1(A000110(n)) = A000203(A000110(n)).

a(n) = sigma_1(1/e*Sum_{k >=0} k^n/(k!)).

MATHEMATICA

Table[DivisorSigma[1, BellB[n]], {n, 0, 22}]

PROG

(MAGMA) [DivisorSigma(1, Bell(n)): n in [0..30]]; // Vincenzo Librandi, Sep 19 2015

(PARI) a000110(n) = n! * polcoeff( exp( exp( x + x * O(x^n)) - 1), n);

vector(30, n, sigma(a000110(n-1))) \\ Altug Alkan, Sep 26 2015

(PARI) a000110(n) = round(exp(-1)*suminf(k=0, 1.0*k^n/k!));

vector(30, n, sigma(a000110(n-1))) \\ Altug Alkan, Oct 04 2015

CROSSREFS

Cf. A000110, A000203.

Sequence in context: A296215 A152761 A295761 * A109155 A294381 A081072

Adjacent sequences:  A262346 A262347 A262348 * A262350 A262351 A262352

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Sep 18 2015

EXTENSIONS

More terms from Vincenzo Librandi, Sep 19 2015

STATUS

approved

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Last modified October 19 16:17 EDT 2019. Contains 328223 sequences. (Running on oeis4.)