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A073913 Number of staircase polygons on the square lattice with perimeter 2n and one (possibly rotated) staircase polygonal hole. 1
1, 12, 94, 604, 3461, 18412, 93016, 452500, 2139230, 9890404, 44921002, 201099320, 889594210, 3896177956, 16920602244, 72954802376, 312595497011, 1332153819572, 5650155211024, 23864065957572, 100418115489408 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The old entry with this A-number was a duplicate of A070844.

LINKS

Iwan Jensen, Table of n, a(n) for n = 0..117 [Data from web page]]

Iwan Jensen, Polygon enumerations.

Iwan Jensen, Andrew Rechnitzer, The exact perimeter generating function for a model of punctured staircase polygons, J. Phys. A: Math. Theor. 41 (2008) 215002, Table 1. [From R. J. Mathar, Mar 02 2009]

CROSSREFS

Cf. A057410, A057414.

Sequence in context: A044263 A044644 A173348 * A057410 A045894 A045829

Adjacent sequences:  A073910 A073911 A073912 * A073914 A073915 A073916

KEYWORD

nonn

AUTHOR

Olivier Gérard, Feb 14 2009, based on data from the web site of Iwan Jensen.

STATUS

approved

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Last modified June 26 02:24 EDT 2017. Contains 288749 sequences.