A038002 Number of connected functions on n points with a single labeled point.

0, 1, 3, 9, 27, 81, 242, 722, 2150, 6395, 19003, 56428, 167458, 496724, 1472835, 4365692, 12936998, 38327764, 113529027, 336221554, 995586119, 2947641940, 8726093434, 25829729702, 76450357119, 226257478851, 669566448376, 1981320898874, 5862583555761

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Formula

G.f.: B(x)(B(x)+1) where B(x) is g.f. of A000107.

a(n) = Sum_{k=1..n} k * A339067(n,k). - Alois P. Heinz, Dec 04 2020

G.f.: A000081(x) / (1 - A000081(x))^2, where A000081(x) is the g.f. of A000081. - Vaclav Kotesovec, Jan 03 2021

Crossrefs

Cf. A000107, A027853, A339067.

Sequence in context: A022014 A181140 A291007 * A272338 A249019 A216096

Adjacent sequences: A037999 A038000 A038001 * A038003 A038004 A038005

Keyword

nonn

Author

Christian G. Bower

Status

approved