login
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
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).
CROSSREFS
KEYWORD
nonn
AUTHOR
Ran Pan, Jul 05 2016
STATUS
approved