536870855

Appears in sequences

• The number of order-preserving partial isometries (of an n-chain) of fix zero (fix of alpha = 0). Equivalently, the number of order-preserving partial derangement isometries (of an n-chain).at n=28A183155
• Number of ways to select 3 or more collinear points from a 4 X n grid.at n=26A355552