Number of permutations of length n without 3-sequences.
A002628
Number of permutations of length n without 3-sequences.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =21a(5) =106a(6) =643a(7) =4547a(8) =36696a(9) =332769a(10) =3349507a(11) =37054436a(12) =446867351a(13) =5834728509a(14) =82003113550
External references
- oeis: A002628