61140

Appears in sequences

• Number of nX4 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.at n=7A224154
• Number of length 2+2 0..n arrays with the sum of second differences squared multiplied by some arrangement of +-1 equal to zero.at n=38A250321
• a(n) = 1 + Sum_{k=0..floor((n-1)/2)} a(k) * a(n-2*k-1).at n=17A351972