Number of set partitions of [n] such that j is member of block b only if b = 1 or at least one of j-1, ..., j-8 is member of a block >= b-1.

A287671

Number of set partitions of [n] such that j is member of block b only if b = 1 or at least one of j-1, ..., j-8 is member of a block >= b-1.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =52a(6) =203a(7) =877a(8) =4140a(9) =21147a(10) =115975a(11) =678569a(12) =4213333a(13) =27634757a(14) =190697165a(15) =1379679500a(16) =10433619205a(17) =82253035850a(18) =674373619108

External references