Number of permutations of length n which avoid the patterns 1432, 2134, 2143.

A116809

Number of permutations of length n which avoid the patterns 1432, 2134, 2143.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =21a(4) =76a(5) =273a(6) =971a(7) =3439a(8) =12172a(9) =43098a(10) =152649a(11) =540730a(12) =1915445a(13) =6785029a(14) =24034177a(15) =85134498a(16) =301565746a(17) =1068215101a(18) =3783864272a(19) =13403320805a(20) =47477655647a(21) =168176809999a(22) =595721056436

External references