Number of noncrossing permutations of [n] avoiding 213 (and by symmetry 132, 213, or 312).
A383771
Number of noncrossing permutations of [n] avoiding 213 (and by symmetry 132, 213, or 312).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =19a(4) =102a(5) =590a(6) =3588a(7) =22617a(8) =146460a(9) =968520a(10) =6513034a(11) =44403604a(12) =306209746a(13) =2132165062a(14) =14970030506a(15) =105862919427a(16) =753344866662
External references
- oeis: A383771