A228551 Number of connected labeled graded posets on n vertices.

1, 1, 2, 12, 146, 2820, 79682, 3109932, 163268786, 11373086100, 1049057429762, 128748967088412, 21220651011079346, 4747770003765805380, 1456585782002699624642, 6390825031791150383749864

Offset

0,3

Comments

Here 'graded' is to be intended as in A001833.

Links

Table of n, a(n) for n=0..15.

David A. Klarner, The number of graded partially ordered sets, Journal of Combinatorial Theory, vol.6, no.1, pp.12-19, (January-1969).

Formula

E.g.f.: 1 + log(F(x)), where F(x) is the e.g.f. of A001833.

Crossrefs

Cf. A001833.

Sequence in context: A324140 A296137 A086928 * A001927 A289987 A105558

Adjacent sequences: A228548 A228549 A228550 * A228552 A228553 A228554

Keyword

nonn

Author

Daniele P. Morelli, Aug 25 2013

Status

approved