Number of n X 3 binary arrays indicating whether each 2 X 2 subblock of a larger binary array has lexicographically increasing rows and columns, for some larger (n+1) X 4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

A227086

Number of n X 3 binary arrays indicating whether each 2 X 2 subblock of a larger binary array has lexicographically increasing rows and columns, for some larger (n+1) X 4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Terms

    a(0) =7a(1) =29a(2) =99a(3) =302a(4) =842a(5) =2177a(6) =5281a(7) =12128a(8) =26548a(9) =55684a(10) =112389a(11) =219051a(12) =413531a(13) =758154a(14) =1353017a(15) =2355283a(16) =4006629a(17) =6671623a(18) =10890535a(19) =17450956a(20) =27483624a(21) =42589055a(22) =65002969a(23) =97810106a(24) =145217866a(25) =212903302a(26) =308449369a(27) =441889009a(28) =626378657

External references