Number of n X 2 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.
A230269
Number of n X 2 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.
Terms
- a(0) =0a(1) =0a(2) =2a(3) =8a(4) =30a(5) =108a(6) =386a(7) =1376a(8) =4902a(9) =17460a(10) =62186a(11) =221480a(12) =788814a(13) =2809404a(14) =10005842a(15) =35636336a(16) =126920694a(17) =452034756a(18) =1609945658a(19) =5733906488a(20) =20421610782a(21) =72732645324a(22) =259041157538a(23) =922588763264
External references
- oeis: A230269