Number of (3+1)X(n+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw.

A253328

Number of (3+1)X(n+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw.

Terms

    a(0) =121a(1) =377a(2) =1217a(3) =3787a(4) =11506a(5) =31999a(6) =86922a(7) =217799a(8) =537127a(9) =1242718a(10) =2846066a(11) =6208632a(12) =13461284a(13) =28145490a(14) =58668559a(15) =119104209a(16) =241640885a(17) =481269481a(18) =959688428a(19) =1890550722a(20) =3733605722a(21) =7319677531a(22) =14396259965a(23) =28207082638

External references