1150036

Appears in sequences

• Number of n-element unlabeled N-free posets.at n=12A202182
• Number of (n+1)X(3+1) 0..3 arrays with the upper median plus the lower median of every 2X2 subblock equal.at n=2A237002
• T(n,k) = Number of (n+1) X (k+1) 0..3 arrays with the upper median plus the lower median of every 2 X 2 subblock equal.at n=12A237007