Number of nX3 0..1 arrays with every element equal to 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A300460

Number of nX3 0..1 arrays with every element equal to 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =0a(1) =2a(2) =2a(3) =8a(4) =22a(5) =68a(6) =212a(7) =652a(8) =2017a(9) =6225a(10) =19229a(11) =59393a(12) =183451a(13) =566633a(14) =1750167a(15) =5405795a(16) =16697038a(17) =51572664a(18) =159294072a(19) =492016422a(20) =1519706056a(21) =4693962286a(22) =14498384074a(23) =44781599826a(24) =138318289075a(25) =427227905079

External references