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A050204 Number of n X n alternating sign matrices without the restriction that -1's be "bordered" by +1's. 3
1, 2, 21, 1344, 628080 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

CROSSREFS

Cf. A005130.

Sequence in context: A015193 A022488 A052157 * A022470 A080815 A114846

Adjacent sequences:  A050201 A050202 A050203 * A050205 A050206 A050207

KEYWORD

nonn

AUTHOR

Eric Weisstein (eric(AT)weisstein.com)

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Last modified February 17 14:50 EST 2012. Contains 206050 sequences.