The number of upper-triangular matrices with at least one nonzero entry in each row and whose entries sum to n.
A158691
The number of upper-triangular matrices with at least one nonzero entry in each row and whose entries sum to n.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =12a(4) =61a(5) =380a(6) =2815a(7) =24213a(8) =237348a(9) =2612681a(10) =31915787a(11) =428481472a(12) =6271362282a(13) =99388642292
External references
- oeis: A158691