Number of permutations of length n which avoid the patterns 4213 and 3142.

A165541

Number of permutations of length n which avoid the patterns 4213 and 3142.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =89a(6) =379a(7) =1664a(8) =7460a(9) =33977a(10) =156727a(11) =730619a(12) =3436710a(13) =16291842a(14) =77758962a(15) =373369867a(16) =1802399037a(17) =8742691627a(18) =42590945206a(19) =208300979739

External references