Number of (2+1)X(n+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw.

A253327

Number of (2+1)X(n+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw.

Terms

    a(0) =44a(1) =126a(2) =373a(3) =1026a(4) =2797a(5) =6936a(6) =17197a(7) =39616a(8) =91571a(9) =200800a(10) =442031a(11) =937998a(12) =1997242a(13) =4147312a(14) =8635487a(15) =17680582a(16) =36274902a(17) =73603454a(18) =149571217a(19) =301772250a(20) =609502075a(21) =1225424712a(22) =2465561705a(23) =4946547564a(24) =9928863677a(25) =19894339804

External references