Number of n X 4 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 5 binary array having two adjacent 1's and two adjacent 0's, with rows and columns of the latter in lexicographically nondecreasing order.
A227331
Number of n X 4 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 5 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) =15a(1) =104a(2) =708a(3) =4917a(4) =33297a(5) =204206a(6) =1108382a(7) =5361624a(8) =23477312a(9) =94474684a(10) =353596604a(11) =1242207201a(12) =4125406694a(13) =13026205724a(14) =39292608858a(15) =113681479364a(16) =316556625809a(17) =850933663116
External references
- oeis: A227331