Number of n X 2 0..1 arrays with every element equal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

A297917

Number of n X 2 0..1 arrays with every element equal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

Terms

    a(0) =1a(1) =4a(2) =17a(3) =61a(4) =216a(5) =793a(6) =2907a(7) =10622a(8) =38809a(9) =141849a(10) =518472a(11) =1894989a(12) =6926071a(13) =25314486a(14) =92523373a(15) =338168845a(16) =1235992136a(17) =4517496689a(18) =16511251075a(19) =60347893838a(20) =220568887889a(21) =806169548561

External references