294961

Appears in sequences

• Number of (n+1) X (3+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=15A253430
• a(n) = Sum_{k=1..n+1} (-1)^(k-1) k (n - k + 1)!.at n=8A374651