A274646 Number of linear extensions of the one-level grid poset G[(3^n), (0^(n-1)), (0^(n-1))].

1, 70, 26599, 29609650, 72574079902, 332014782982540, 2545213373338499072, 30302687687176712355840, 529556871638491591748878336, 13004213964445490176628310933504, 433440210434110194677894532074307584

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 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 number of linear extensions of the one-level grid poset G[(2^n), (0^(n-1)), (0^(n-1))] is given by A274645(n).

Links

Table of n, a(n) for n=1..11.

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, A274645.

Sequence in context: A177637 A145410 A177638 * A005983 A200313 A177642

Adjacent sequences: A274643 A274644 A274645 * A274647 A274648 A274649

Keyword

nonn

Author

Ran Pan, Jun 30 2016

Status

approved