A235610 Array read by antidiagonals: T(n,k) = number of possible positions in standard Connect Four play on a board of height n and width k (n>=1, k>=1).

2, 3, 5, 4, 18, 13, 5, 58, 116, 35, 6, 179, 869, 741, 96, 7, 537, 6000, 12031, 4688, 267, 8, 1571, 38310, 161029, 158911, 29737, 750, 9, 4587, 235781, 1706255, 3945711, 2087325, 189648, 2118

Offset

1,1

Links

Table of n, a(n) for n=1..36.

John Tromp, John's Connect Four Playground, viewed Jan 23 2014.

Example

The array as given on the Tromp web site:
height
------
8:      9       13343   8424616 1104642469
7:      8       4587    1417322 135385909       14171315454
6:      7       1571    235781  15835683        1044334437      69173028785     4531985219092
5:      6       537     38310   1706255 69763700        2818972642      112829665923
4:      5       179     6000    161029  3945711 94910577        2265792710      54233186631
3:      4       58      869     12031   158911  2087325 27441956        362940958
2:      3       18      116     741     4688    29737   189648  1216721
1:      2       5       13      35      96      267     750     2118
-------------------------------------------------------------------------------
-:      1       2       3       4       5       6       7  <- width

Crossrefs

Cf. A212693, A090224, A013582, A235611, A235612.

Sequence in context: A095753 A139537 A111631 * A118141 A343767 A175210

Adjacent sequences: A235607 A235608 A235609 * A235611 A235612 A235613

Keyword

nonn,tabl

Author

N. J. A. Sloane, Jan 23 2014

Status

approved