A071097 Number of ways to tile Aztec diamond of order n with 2 squares removed with dominoes.

2, 8, 160, 4608, 393216, 37748736, 11022630912, 5315022028800, 6333186975989760, 10808639105689190400, 48595641419178600038400, 381803330140010815527321600, 6932464219998129539435095654400

Offset

2,1

References

J. Propp, Enumeration of matchings: problems and progress, pp. 255-291 in L. J. Billera et al., eds, New Perspectives in Algebraic Combinatorics, Cambridge, 1999 (see Problem 7).

Links

Table of n, a(n) for n=2..14.

J. Propp, Updated article

J. Propp, Enumeration of matchings: problems and progress, in L. J. Billera et al. (eds.), New Perspectives in Algebraic Combinatorics

Example

From Andrew Howroyd, Mar 07 2016: (Start)
The 2 removed squares are central and separated by a knights move.
Illustration of n = 4:
*            ++
*           ++++
*          ++++++
*         +++++ ++
*         +++ ++++
*          ++++++
*           ++++
*            ++
(End)

Crossrefs

Sequence in context: A012571 A018926 A012432 * A012537 A012540 A346164

Adjacent sequences: A071094 A071095 A071096 * A071098 A071099 A071100

Keyword

nonn

Author

N. J. A. Sloane, May 28 2002

Extensions

a(11)-a(14) from Andrew Howroyd, Mar 07 2016

Status

approved