Number of 2Xn arrays containing n copies of 0..2-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0.

A267725

Number of 2Xn arrays containing n copies of 0..2-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =3a(4) =5a(5) =12a(6) =26a(7) =60a(8) =143a(9) =353a(10) =879a(11) =2200a(12) =5528a(13) =13963a(14) =35421a(15) =90122a(16) =229729a(17) =586438a(18) =1498966a(19) =3836099a(20) =9827905a(21) =25202549a(22) =64683193a(23) =166137751a(24) =427022480a(25) =1098291533a(26) =2826500851a(27) =7278246356a(28) =18751418071a(29) =48334451894

External references