Square root of number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with every occupancy equal to zero or two.

A221313

Square root of number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with every occupancy equal to zero or two.

Terms

    a(0) =1a(1) =4a(2) =9a(3) =23a(4) =57a(5) =142a(6) =353a(7) =878a(8) =2183a(9) =5428a(10) =13496a(11) =33556a(12) =83432a(13) =207441a(14) =515770a(15) =1282382a(16) =3188443

External references