Number of involutions of length 2n which are invariant under the reverse-complement map and have no decreasing subsequences of length 6.

A145847

Number of involutions of length 2n which are invariant under the reverse-complement map and have no decreasing subsequences of length 6.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =19a(4) =67a(5) =246a(6) =947a(7) =3746a(8) =15213a(9) =62950a(10) =264920a(11) =1129965a(12) =4877215a(13) =21262918a(14) =93522756a(15) =414532163a(16) =1850047621a(17) =8307290058a(18) =37507875950a(19) =170191051327a(20) =775719275151

External references