Number of 3-stack sortable permutations on n letters.
A134664
Number of 3-stack sortable permutations on n letters.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =24a(4) =114a(5) =606a(6) =3494a(7) =21426a(8) =137901a(9) =922862a(10) =6377818a(11) =45281958a(12) =328969075a(13) =2437728712a(14) =18378435667a(15) =140675908516
External references
- oeis: A134664