311200

Appears in sequences

• Number of (n+2)X(2+2) 0..1 arrays with no 3x3 subblock diagonal sum 3 and no antidiagonal sum 3 and no row sum 0 and no column sum 0.at n=9A256742
• a(0)=1; a(1)=1; for n>1, a(n) = a(n-1) + 3*n*a(n-2).at n=9A351531