617500

Appears in sequences

• Number of (n+1)X(1+1) 0..4 arrays with row and column sums nondecreasing, and no adjacent elements equal.at n=6A233309
• T(n,k)=Number of (n+1)X(k+1) 0..4 arrays with row and column sums nondecreasing, and no adjacent elements equal.at n=21A233311
• T(n,k)=Number of (n+1)X(k+1) 0..4 arrays with row and column sums nondecreasing, and no adjacent elements equal.at n=27A233311
• Number of 4-cycles in the n X n rook graph.at n=19A288962