11661506218
domain: N
Appears in sequences
- Hertzsprung's problem: ways to arrange n non-attacking kings on an n X n board, with 1 in each row and column. Also number of permutations of length n without rising or falling successions.at n=14A002464
- Permanent of the (0,1)-matrix with ij-th entry equal to zero iff (i=1,j=1),(i=1,j=2),(i=1,j=3),(i=2,j=3),(i=3,j=3),... In other words, the ij-th entry of the matrix is zero iff it is on the path which start from the entry (i=1,j=1) and moves in the matrix alternating 3 steps to the right to 3 steps down.at n=14A098926
- Triangle read by rows: T(n,k) is the number of ways to place k non-attacking kings in each row and column of an n X n board, 0 <= k <= floor(n/4) + [n=1].at n=33A387098