Number of nX4 0..1 arrays with every element equal to 1, 2, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A301357

Number of nX4 0..1 arrays with every element equal to 1, 2, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =2a(1) =15a(2) =34a(3) =101a(4) =320a(5) =1167a(6) =3961a(7) =13974a(8) =49388a(9) =171718a(10) =595933a(11) =2069269a(12) =7184407a(13) =24983410a(14) =87005062a(15) =303301112a(16) =1058018103a(17) =3691794974a(18) =12883245735a(19) =44960338427a(20) =156905033430a(21) =547579453383

External references