Number of nX4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 1 0 vertically.

A207881

Number of nX4 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 1 0 vertically.

Terms

    a(0) =9a(1) =81a(2) =221a(3) =575a(4) =1673a(5) =4881a(6) =14825a(7) =45411a(8) =141381a(9) =443159a(10) =1399925a(11) =4442717a(12) =14159449a(13) =45263327a(14) =145061281a(15) =465794335a(16) =1498036809a(17) =4823779033a(18) =15548389529a(19) =50156459339a(20) =161898944109a(21) =522854621863

External references