Number of permutations of [n] having exactly 2 strong fixed blocks.

A225963

Number of permutations of [n] having exactly 2 strong fixed blocks.

Terms

    a(0) =1a(1) =5a(2) =25a(3) =134a(4) =815a(5) =5657a(6) =44549a(7) =394266a(8) =3883182a(9) =42174500a(10) =500942458a(11) =6460077110a(12) =89875729761

External references