520784

Appears in sequences

• a(n) = n * n! * b(n), where b(n) = ((n-1)*(n-3)*b(n-1) - b(n-2) + b(n-3))/(n*(n - 1)) and b(0) = b(1) = 1, b(2) = -1.at n=11A158802
• Number of (n+2)X5 0..2 matrices with each 3X3 subblock idempotent.at n=22A224601