156768

Appears in sequences

• There are three equivalent descriptions: 1. Number of (horizontally or vertically) connected arrays of 1..n on rectangular grid (otherwise zero) with only one local maximum. 2. Number of n-polyominoes labeled 1...n such that each successive labeled cell is the neighbor of a previously labeled cell. 3. Number of connected n-step paths on a rectangular lattice, diagonal or repeated steps not allowed.at n=7A007846
• a(n) = n*(2*n+5)*(2*n+7).at n=32A035329
• Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001111.at n=10A260365
• Number of (undirected) paths in the complete bipartite graph K_{m,n} (triangle read by rows with m = 1..n and n = 1..).at n=31A307027