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A304984 Number of labeled clutters (connected antichains) spanning some subset of {1,...,n} with singleton edges allowed. 7
1, 2, 7, 56, 1533, 210302, 496838435, 309068803876372, 14369391923126181310256825 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..8.

FORMULA

Binomial transform of A304985(n > 0).

EXAMPLE

The a(2) = 7 clutters:

  {}

  {{1}}

  {{2}}

  {{1,2}}

  {{1},{1,2}}

  {{2},{1,2}}

  {{1},{2},{1,2}}

CROSSREFS

Cf. A048143, A198085, A261006, A304912, A304981, A304982, A304983, A304984, A304985, A304986.

Sequence in context: A182055 A211209 A271440 * A002658 A175818 A034939

Adjacent sequences:  A304981 A304982 A304983 * A304985 A304986 A304987

KEYWORD

nonn

AUTHOR

Gus Wiseman, May 23 2018

STATUS

approved

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Last modified December 15 20:37 EST 2018. Contains 318154 sequences. (Running on oeis4.)