Number of permutations of [n] that avoid the patterns 2-41-3, 3-14-2, 2-1-4-3, and 4-5-3-1-2.

A363813

Number of permutations of [n] that avoid the patterns 2-41-3, 3-14-2, 2-1-4-3, and 4-5-3-1-2.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =78a(6) =295a(7) =1114a(8) =4166a(9) =15390a(10) =56167a(11) =202738a(12) =724813a(13) =2570276a(14) =9052494a(15) =31702340a(16) =110503497a(17) =383691578a(18) =1328039043a(19) =4584708230a(20) =15793983638a(21) =54315199642a(22) =186526735307a(23) =639831906594

External references