Number of nX4 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

A301880

Number of nX4 0..1 arrays with every element equal to 0, 1 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =5a(1) =18a(2) =58a(3) =203a(4) =673a(5) =2340a(6) =7883a(7) =27175a(8) =92411a(9) =316916a(10) =1082302a(11) =3703582a(12) =12666854a(13) =43318597a(14) =148204170a(15) =506815629a(16) =1733886818a(17) =5929952262a(18) =20285442903a(19) =69382426261a(20) =237332736304a(21) =811785135443

External references