Number of permutations of [n] having exactly 3 strong fixed blocks.

A225964

Number of permutations of [n] having exactly 3 strong fixed blocks.

Terms

    a(0) =1a(1) =9a(2) =63a(3) =419a(4) =2868a(5) =20932a(6) =165662a(7) =1432746a(8) =13578086a(9) =140951642a(10) =1598792812a(11) =19739303596a(12) =264041415799

External references