

A013582


Number of positions in game "Connect Four" (played on usual 6row, 7column board) after n moves, up to reflection.


4



1, 4, 25, 121, 568, 2144, 8231, 27473, 92244, 279241, 831581, 2284733, 6118941, 15465573, 37720667, 88273017, 197300906, 429114775, 881951878, 1784140720, 3373100313, 6336692489, 11005448210, 19131647821, 30415473928, 48633111249
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OFFSET

0,2


LINKS

Sean A. Irvine, Table of n, a(n) for n = 0..42
John Tromp, John's Connect Four Playground, viewed Jan 23 2014.
Eric Weisstein's World of Mathematics, ConnectFour


CROSSREFS

Cf. A212693.
Sequence in context: A273023 A013187 A069639 * A260373 A175733 A240479
Adjacent sequences: A013579 A013580 A013581 * A013583 A013584 A013585


KEYWORD

nonn,fini,full


AUTHOR

Russ Cox


EXTENSIONS

Name clarified by Charles R Greathouse IV, Dec 01 2013
a(3)a(13) corrected by Sean A. Irvine, Aug 09 2018. The corrected values were confirmed by Russ Cox and extended through a(15), Aug 13 2018
a(16)a(17) from Sean A. Irvine, Aug 15 2018
Remaining terms a(18)a(42) from Sean A. Irvine, Oct 02 2018


STATUS

approved



