a(n) is the number of permutations of [1..n] that avoid the consecutive pattern 1324 (equally, the permutations that avoid 4231).

A113228

a(n) is the number of permutations of [1..n] that avoid the consecutive pattern 1324 (equally, the permutations that avoid 4231).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =110a(6) =632a(7) =4229a(8) =32337a(9) =278204a(10) =2659223a(11) =27959880a(12) =320706444a(13) =3985116699a(14) =53328433923a(15) =764610089967

External references