A034770 - OEIS

A034770

Dirichlet convolution of Bell numbers with themselves.

1, 2, 4, 11, 30, 108, 406, 1764, 8284, 42324, 231950, 1357264, 8427194, 55289280, 381798704, 2765918869, 20960284294, 165729748096, 1364153612318, 11665484452558, 103448316471556, 949739632545452, 9013431476894646

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..23.

MATHEMATICA

Table[Sum[BellB[n/d - 1]*BellB[d - 1], {d, Divisors[n]}], {n, 1, 25}] (* Vaclav Kotesovec, Sep 10 2019 *)

CROSSREFS

Sequence in context: A275310 A102814 A193059 * A276687 A298891 A002387

Adjacent sequences: A034767 A034768 A034769 * A034771 A034772 A034773

KEYWORD

nonn

AUTHOR

Erich Friedman

STATUS

approved