Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010001.

A260173

Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010001.

Terms

    a(0) =409a(1) =1001a(2) =2598a(3) =6973a(4) =19701a(5) =55849a(6) =153286a(7) =432380a(8) =1232980a(9) =3453740a(10) =9694328a(11) =27459576a(12) =77441354a(13) =217625342a(14) =613977178a(15) =1733263382a(16) =4880225452a(17) =13751170422a(18) =38794513220a(19) =109345894200a(20) =308089966994a(21) =868658498318

External references