1,3

a(n) is the number of hyperforests with n unlabeled nodes without isolated vertices. This follows from the fact that for n>0 A134955(n-1) counts the hyperforests of order n with one or more isolated nodes.

Cf. A134955, A144958(unlabeled forests without isolated vertices).

Sequence in context: A092764 A059075 A121134 this_sequence A131347 A079225 A139466

Adjacent sequences: A144956 A144957 A144958 this_sequence A144960 A144961 A144962

nonn

W. Bomfim (webonfim(AT)bol.com.br), Sep 27 2008