Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks are <= four.
A287254
Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks are <= four.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =52a(6) =202a(7) =857a(8) =3933a(9) =19373a(10) =101755a(11) =566712a(12) =3331349a(13) =20592862a(14) =133439286a(15) =903926271a(16) =6385918342a(17) =46950260915a(18) =358560107124
External references
- oeis: A287254