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A038002 Number of connected functions on n points with a single labeled point. 3
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified November 28 19:34 EST 2021. Contains 349415 sequences. (Running on oeis4.)