Number of permutations in S_{2*n+3} containing the pattern 2143...(2n)(2n-1).

A271648

Number of permutations in S_{2*n+3} containing the pattern 2143...(2n)(2n-1).

Terms

    a(0) =6a(1) =119a(2) =2279a(3) =18042a(4) =83921a(5) =284428a(6) =782795a(7) =1859374a(8) =3957717a(9) =7738336a(10) =14140143a(11) =24449570a(12) =40377369a(13) =64143092a(14) =98567251a(15) =147171158a(16) =214284445a(17) =305160264a(18) =426098167a(19) =584574666a(20) =789381473a(21) =1050771420

External references