Triangle read by rows: T(n,k) gives number of r-bicoverings of an n-set with k blocks, n >= 2, k = 3..n+floor(n/2).

A060052

Triangle read by rows: T(n,k) gives number of r-bicoverings of an n-set with k blocks, n >= 2, k = 3..n+floor(n/2).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =0a(4) =15a(5) =25a(6) =3a(7) =0a(8) =30a(9) =222a(10) =226a(11) =40a(12) =0a(13) =30a(14) =1230a(15) =3670a(16) =2706a(17) =535a(18) =15a(19) =0a(20) =0a(21) =5040a(22) =39900a(23) =69450a(24) =40405a(25) =8141a(26) =420a(27) =0a(28) =0a(29) =15120

External references