Number of n X 2 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 3 binary array having two adjacent 1's and two adjacent 0's, with rows and columns of the latter in lexicographically nondecreasing order.
A227329
Number of n X 2 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 3 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) =4a(1) =11a(2) =34a(3) =104a(4) =285a(5) =683a(6) =1469a(7) =2906a(8) =5383a(9) =9457a(10) =15904a(11) =25780a(12) =40493a(13) =61887a(14) =92339a(15) =134870a(16) =193271a(17) =272245a(18) =377566a(19) =516256a(20) =696781a(21) =929267a(22) =1225737a(23) =1600370a(24) =2069783a(25) =2653337a(26) =3373468a(27) =4256044a(28) =5330749a(29) =6631495
External references
- oeis: A227329