Number of permutations of length n which avoid the patterns 4123, 1324, and 3124.

A277221

Number of permutations of length n which avoid the patterns 4123, 1324, and 3124.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =78a(6) =297a(7) =1143a(8) =4419a(9) =17119a(10) =66386a(11) =257621a(12) =1000407a(13) =3887666a(14) =15119991a(15) =58856167a(16) =229312425a(17) =894263633a(18) =3490636794a(19) =13637575699a(20) =53327459013a(21) =208703945330a(22) =817447047177

External references