Number of Dumont permutations of the fourth kind of length 2n avoiding the pattern 312.

A343795

Number of Dumont permutations of the fourth kind of length 2n avoiding the pattern 312.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =10a(4) =39a(5) =174a(6) =872a(7) =4805a(8) =28474a(9) =178099a(10) =1160173a(11) =7803860a(12) =53924841a(13) =381640934a(14) =2761331130a(15) =20400560942a(16) =153738854242

External references