Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks and between consecutive elements within the blocks are not larger than four.
A287583
Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks and between consecutive elements within the blocks are not larger than four.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =52a(6) =187a(7) =677a(8) =2439a(9) =8707a(10) =30871a(11) =108696a(12) =380653a(13) =1328193a(14) =4623194a(15) =16065161a(16) =55763738a(17) =193430602a(18) =670683122a(19) =2324853720a(20) =8057594663a(21) =27923827498a(22) =96765523944a(23) =335314355594
External references
- oeis: A287583