Number of permutations of [n] that avoid the shuffle pattern s-k-t, where s = 12 and t = 1234.

A324136

Number of permutations of [n] that avoid the shuffle pattern s-k-t, where s = 12 and t = 1234.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =720a(7) =5025a(8) =39926a(9) =355538a(10) =3505864a(11) =37917861a(12) =446320694a(13) =5680229144a(14) =77727692650

External references