Triangular array read by rows: T(n,k) is the number of blocks of size k in all set partitions of {1,2,...,n}.

A175757

Triangular array read by rows: T(n,k) is the number of blocks of size k in all set partitions of {1,2,...,n}.

Terms

    a(0) =1a(1) =2a(2) =1a(3) =6a(4) =3a(5) =1a(6) =20a(7) =12a(8) =4a(9) =1a(10) =75a(11) =50a(12) =20a(13) =5a(14) =1a(15) =312a(16) =225a(17) =100a(18) =30a(19) =6a(20) =1a(21) =1421a(22) =1092a(23) =525a(24) =175a(25) =42a(26) =7a(27) =1a(28) =7016a(29) =5684

External references