Number of 3Xn 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

A302000

Number of 3Xn 0..1 arrays with every element equal to 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =0a(1) =5a(2) =5a(3) =26a(4) =84a(5) =309a(6) =1108a(7) =3979a(8) =14314a(9) =51440a(10) =185083a(11) =665473a(12) =2393298a(13) =8606453a(14) =30950505a(15) =111303112a(16) =400265922a(17) =1439423515a(18) =5176415456a(19) =18615274437a(20) =66943726862a(21) =240741120250a(22) =865746384343

External references