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A274764 Number of linear extensions of the one-level grid poset G[(1^n), (1^(n-1)), (1^(n-1))]. 0
1, 20, 962, 75080, 8133732, 1127589120, 190416834360, 37902843124640, 8686847271179984, 2252403871470920960, 651771144516905730048, 208193858907016903262208, 72758882836839703611703296, 27613191886304138293279719424, 11308972154842887758316960743424, 4971172331379604809443266242019328 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The definition of a one-level grid poset can be found in the Pan links. The number of linear extensions of the one-level grid poset G[(0^n), (0^(n-1)), (0^(n-1))] is given by Catalan number A000108(n), the number of linear extensions of the one-level grid poset G[(1^n), (0^(n-1)), (0^(n-1))] is given by A274644(n) and the number of linear extensions of the one-level grid poset G[(1^n), (1^(n-1)), (0^(n-1))] 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 one-level grid-like posets), Project P.

CROSSREFS

Cf. A000108, A274644, A274763.

Sequence in context: A066798 A072035 A269413 * A069578 A269644 A128482

Adjacent sequences:  A274761 A274762 A274763 * A274765 A274766 A274767

KEYWORD

nonn

AUTHOR

Ran Pan, Jul 05 2016

STATUS

approved

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Last modified September 26 06:24 EDT 2017. Contains 292502 sequences.