

A274764


Number of linear extensions of the onelevel grid poset G[(1^n), (1^(n1)), (1^(n1))].


0



1, 20, 962, 75080, 8133732, 1127589120, 190416834360, 37902843124640, 8686847271179984, 2252403871470920960, 651771144516905730048, 208193858907016903262208, 72758882836839703611703296, 27613191886304138293279719424, 11308972154842887758316960743424, 4971172331379604809443266242019328
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OFFSET

1,2


COMMENTS

The definition of a onelevel grid poset can be found in the Pan links. The number of linear extensions of the onelevel grid poset G[(0^n), (0^(n1)), (0^(n1))] is given by Catalan number A000108(n), the number of linear extensions of the onelevel grid poset G[(1^n), (0^(n1)), (0^(n1))] is given by A274644(n) and the number of linear extensions of the onelevel grid poset G[(1^n), (1^(n1)), (0^(n1))] is given by A274763(n).


LINKS

Table of n, a(n) for n=1..16.
Ran Pan, Problem 1, Project P.
Ran Pan, Algorithmic Solution to Problem 1 (and linear extensions of general onelevel gridlike posets), Project P.


CROSSREFS

Cf. A000108, A274644, A274763.
Sequence in context: A066798 A072035 A269413 * A069578 A269644 A349964
Adjacent sequences: A274761 A274762 A274763 * A274765 A274766 A274767


KEYWORD

nonn


AUTHOR

Ran Pan, Jul 05 2016


STATUS

approved



