Number of permutations of length n which avoid the patterns 1342, 3214, 4312.

Terms

a(0) =1a(1) =2a(2) =6a(3) =21a(4) =71a(5) =213a(6) =569a(7) =1389a(8) =3175a(9) =6927a(10) =14632a(11) =30238a(12) =61596a(13) =124335a(14) =249598a(15) =499492a(16) =997953a(17) =1992420a(18) =3977093a(19) =7939304a(20) =15852025a(21) =31658506a(22) =63240940a(23) =126356805a(24) =252509950a(25) =504690182a(26) =1008848258a(27) =2016839103a(28) =4032297299