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A103904 Number of perfect matchings of an n X (n+1) Aztec rectangle with the third vertex in the topmost row removed. 2
1, 2, 24, 384, 10240, 491520, 44040192, 7516192768, 2473901162496, 1583296743997440, 1981583836043018240, 4869940435459321626624, 23574053482485268906770432, 225305087149939210031640608768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

N. Elkies, G. Kuperberg, M. Larsen and J. Propp, Alternating sign matrices and domino tilings, Journal of Algebraic Combinatorics {\bf 1}, 111-132, 219-234 (1992).

LINKS

Table of n, a(n) for n=1..14.

M. Ciucu, Enumeration of perfect matchings in graphs with reflective symmetry, J. Combin. Theory Ser. A 77 (1997), no. 1, 67-97

C. Krattenthaler, Schur function identities and the number of perfect matchings of Aztec holey rectangles

H. Helfgott and I. M. Gessel, Enumeration of tilings of diamonds and hexagons with defects

FORMULA

n(n-1)/2 * 2^(n(n-1)/2), for n>1.

CROSSREFS

Equals A000217(n-1) * A006125(n). Cf. A095340.

Sequence in context: A288944 A052670 A052736 * A219431 A214688 A003102

Adjacent sequences:  A103901 A103902 A103903 * A103905 A103906 A103907

KEYWORD

nonn

AUTHOR

Ralf Stephan, Feb 21 2005

STATUS

approved

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Last modified November 19 22:34 EST 2019. Contains 329323 sequences. (Running on oeis4.)