Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000101 00010001 or 00010101.

A260605

Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000101 00010001 or 00010101.

Terms

    a(0) =241a(1) =532a(2) =1334a(3) =3388a(4) =8736a(5) =22944a(6) =59758a(7) =156228a(8) =410004a(9) =1074706a(10) =2810634a(11) =7356614a(12) =19275408a(13) =50484816a(14) =132179260a(15) =346084882a(16) =906235472a(17) =2373216196a(18) =6214897284a(19) =16273805984a(20) =42611987122a(21) =111584761940a(22) =292206789126

External references