%I #12 Nov 30 2016 22:28:17

%S 2,3,5,4,18,13,5,58,116,35,6,179,869,741,96,7,537,6000,12031,4688,267,

%T 8,1571,38310,161029,158911,29737,750,9,4587,235781,1706255,3945711,

%U 2087325,189648,2118

%N 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).

%H John Tromp, <a href="http://tromp.github.io/c4/c4.html">John's Connect Four Playground</a>, viewed Jan 23 2014.

%e The array as given on the Tromp web site:

%e height

%e ------

%e 8: 9 13343 8424616 1104642469

%e 7: 8 4587 1417322 135385909 14171315454

%e 6: 7 1571 235781 15835683 1044334437 69173028785 4531985219092

%e 5: 6 537 38310 1706255 69763700 2818972642 112829665923

%e 4: 5 179 6000 161029 3945711 94910577 2265792710 54233186631

%e 3: 4 58 869 12031 158911 2087325 27441956 362940958

%e 2: 3 18 116 741 4688 29737 189648 1216721

%e 1: 2 5 13 35 96 267 750 2118

%e -------------------------------------------------------------------------------

%e -: 1 2 3 4 5 6 7 <- width

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

%K nonn,tabl

%O 1,1

%A _N. J. A. Sloane_, Jan 23 2014