55788550416
domain: N
Appears in sequences
- One quarter the number of nX3 1..4 arrays with no two neighbors of any element equal to each other.at n=19A183355
- Number of 3Xn binary arrays without the pattern 0 1 diagonally or antidiagonally.at n=21A188825
- Number of (n+1)X2 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements.at n=9A203819
- a(1) = 1, a(2) = 2, a(3) = 5; thereafter a(n) = 2 * Sum_{k=1..n-1} a(k).at n=23A257970