1,1

Ray Chandler, Table of n, a(n) for n = 1..10000

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

a(n) = 3*A023396(n).

Cf. A023396.

Sequence in context: A085670 A011410 A298206 * A153841 A334843 A021616

Adjacent sequences: A023404 A023405 A023406 * A023408 A023409 A023410

nonn,base

David W. Wilson

approved