|
| |
|
|
A090224
|
|
Number of possible positions for n discs on a standard 7 X 6 board of Connect-Four.
|
|
3
|
|
|
|
1, 7, 56, 252, 1260, 4620, 18480, 59815, 206780, 605934, 1869840, 5038572, 14164920, 35459424, 91871208, 214864650, 516936420, 1134183050, 2546423880, 5252058812, 11031780760, 21406686756, 42121344720, 76871042612, 141627466344, 242619996500, 417750499600
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Alois P. Heinz, Table of n, a(n) for n = 0..42 (copied from the Victor Allis link)
Victor Allis, A Knowledge-Based Approach of Connect-Four--The Game Is Solved: White Wins.
John Tromp, John's Connect Four Playground, viewed Jan 23 2014.
Eric Weisstein's World of Mathematics, Connect-Four
Wikipedia, Connect Four
|
|
|
EXAMPLE
|
a(2) = 2 * binomial(8,2) since there are binomial(8,2) ways to distribute 2 discs over 7 columns and 2 ways to color them black and white. - John Tromp, May 24 2012
|
|
|
CROSSREFS
|
Cf. A212693 (legal positions after n plies).
Sequence in context: A044526 A153797 A244727 * A237647 A047664 A055345
Adjacent sequences: A090221 A090222 A090223 * A090225 A090226 A090227
|
|
|
KEYWORD
|
nonn,fini,full,nice
|
|
|
AUTHOR
|
Eric W. Weisstein, Nov 24 2003
|
|
|
STATUS
|
approved
|
| |
|
|
