Number of nX3 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

A302724

Number of nX3 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =1a(1) =7a(2) =22a(3) =83a(4) =301a(5) =1079a(6) =4064a(7) =15183a(8) =55012a(9) =207349a(10) =770421a(11) =2830250a(12) =10617371a(13) =39400644a(14) =145704104a(15) =544623685a(16) =2020998479a(17) =7497256552a(18) =27957348859a(19) =103787074017a(20) =385563034716

External references