Number of 3Xn 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

A301824

Number of 3Xn 0..1 arrays with every element equal to 1 or 2 horizontally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =0a(1) =5a(2) =4a(3) =25a(4) =74a(5) =278a(6) =968a(7) =3450a(8) =12210a(9) =43316a(10) =153582a(11) =544554a(12) =1930920a(13) =6846494a(14) =24276442a(15) =86078740a(16) =305217538a(17) =1082235538a(18) =3837379072a(19) =13606528258a(20) =48245865110a(21) =171069584080a(22) =606576433502

External references