A034770 - OEIS

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A034770

Dirichlet convolution of Bell numbers with themselves.

%I #5 Sep 10 2019 12:44:55

%S 1,2,4,11,30,108,406,1764,8284,42324,231950,1357264,8427194,55289280,

%T 381798704,2765918869,20960284294,165729748096,1364153612318,

%U 11665484452558,103448316471556,949739632545452,9013431476894646

%N Dirichlet convolution of Bell numbers with themselves.

%t Table[Sum[BellB[n/d - 1]*BellB[d - 1], {d, Divisors[n]}], {n, 1, 25}] (* _Vaclav Kotesovec_, Sep 10 2019 *)

%K nonn

%O 1,2

%A _Erich Friedman_