1,1

Derived from an infinite sum of the Bell numbers (see formula below).

May also be written as exp(exp(1))/exp(1) = e^e/e.

Table of n, a(n) for n=1..68.

Equals sum(n>=0, Bell(n)/n!), where Bell(n) = A000110(n).

5.5749415247608806239669759227404843057060930975947002119298237838570...

(PARI) exp(exp(1)-1)

Cf. A000110, A001113 (e), A073226 (e^e), A274169.

Sequence in context: A222392 A049471 A049789 * A011500 A003103 A122273

Adjacent sequences: A234470 A234471 A234472 * A234474 A234475 A234476

nonn,cons

Richard R. Forberg, Dec 26 2013

approved