1408893

Appears in sequences

• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X3 el 1,1 1,2 1,3 2,3 3,3 in any orientation.at n=15A146034
• Number of quanimous subsets of {1..n} containing n, meaning there is more than one set partition with equal block-sums.at n=21A371797