Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically.

A208165

Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically.

Terms

    a(0) =9a(1) =81a(2) =287a(3) =981a(4) =2920a(5) =9039a(6) =28681a(7) =89623a(8) =278652a(9) =872602a(10) =2730176a(11) =8525256a(12) =26645271a(13) =83307020a(14) =260355204a(15) =813693708a(16) =2543369350a(17) =7949447810a(18) =24845860649a(19) =77657127110a(20) =242721701342a(21) =758634528231

External references