

A153337


Number of zigzag paths from top to bottom of a 2n1 by 2n1 square whose color is that of the top right corner


4



1, 4, 24, 136, 720, 3624, 17584, 83024, 383904, 1746280, 7839216, 34812144, 153204064, 669108496, 2903267040, 12526343584, 53779871552, 229895033832, 978965187184, 4154438114480, 17575883030496, 74150192517808
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..22.
Joseph Myers, BMO 20082009 Round 1 Problem 1Generalisation


FORMULA

a(n) = (n)2^(2n2)  2(n1)binomial(2n2,n1)


CROSSREFS

A102699, A153334, A153335, A153336, A153338
Sequence in context: A048180 A057391 A071079 * A122690 A183512 A204199
Adjacent sequences: A153334 A153335 A153336 * A153338 A153339 A153340


KEYWORD

easy,nonn


AUTHOR

Joseph Myers, Dec 24 2008


STATUS

approved



