T(n,k) = Number of n X k 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X (k+1) binary array having two adjacent 1's and two adjacent 0's, with rows and columns of the latter in lexicographically nondecreasing order.

A227333

T(n,k) = Number of n X k 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X (k+1) binary array having two adjacent 1's and two adjacent 0's, with rows and columns of the latter in lexicographically nondecreasing order.

Terms

    a(0) =2a(1) =4a(2) =4a(3) =8a(4) =11a(5) =8a(6) =15a(7) =34a(8) =34a(9) =15a(10) =26a(11) =104a(12) =153a(13) =104a(14) =26a(15) =42a(16) =285a(17) =708a(18) =708a(19) =285a(20) =42a(21) =64a(22) =683a(23) =3013a(24) =4917a(25) =3013a(26) =683a(27) =64a(28) =93a(29) =1469

External references