Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s.

A297521

Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s.

Terms

    a(0) =1a(1) =11a(2) =49a(3) =128a(4) =363a(5) =1408a(6) =5079a(7) =16104a(8) =52308a(9) =180643a(10) =616299a(11) =2045926a(12) =6825942a(13) =23061538a(14) =77737769a(15) =260557844a(16) =874178204a(17) =2940510392a(18) =9886875406a(19) =33203436061a(20) =111529068093a(21) =374823089239

External references