Number of permutations of length n which avoid the patterns 1342, 2314, 4213.

Terms

a(0) =1a(1) =2a(2) =6a(3) =21a(4) =73a(5) =241a(6) =757a(7) =2288a(8) =6724a(9) =19365a(10) =54959a(11) =154303a(12) =429733a(13) =1189430a(14) =3276306a(15) =8990037a(16) =24591349a(17) =67093357a(18) =182653717a(19) =496322396a(20) =1346450176a(21) =3647459397a(22) =9868036571a(23) =26666447611a(24) =71984395333a(25) =194127819746