Triangle read by rows: T(n,k) is the number of 2-compositions of n having k nonzero entries in the top row. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.
A181332
Triangle read by rows: T(n,k) is the number of 2-compositions of n having k nonzero entries in the top row. A 2-composition of n is a nonnegative matrix with two rows, such that each column has at least one nonzero entry and whose entries sum up to n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =1a(6) =4a(7) =12a(8) =7a(9) =1a(10) =8a(11) =32a(12) =31a(13) =10a(14) =1a(15) =16a(16) =80a(17) =111a(18) =59a(19) =13a(20) =1a(21) =32a(22) =192a(23) =351a(24) =268a(25) =96a(26) =16a(27) =1a(28) =64a(29) =448
External references
- oeis: A181332