68409

Appears in sequences

• a(n) = -(-1)^n*2*(2*n+1)!*Bernoulli(2*n)/(n!*2^n).at n=5A004193
• Number of nX5 0..1 arrays with every element equal to 2 or 3 king-move adjacent elements, with upper left element zero.at n=16A297811