a(n) is the number of covering relations in the poset P of n X n idempotent matrices over GF(2) ordered by A <= B if and only if AB = BA = A.

A357410

a(n) is the number of covering relations in the poset P of n X n idempotent matrices over GF(2) ordered by A <= B if and only if AB = BA = A.

Terms

    a(0) =0a(1) =1a(2) =12a(3) =224a(4) =6960a(5) =397792a(6) =42001344a(7) =8547291008

External references