OFFSET
1,2
LINKS
Isabel Cação, Helmuth R. Malonek, Maria Irene Falcão, and Graça Tomaz, Intrinsic Properties of a Non-Symmetric Number Triangle, J. Int. Seq., Vol. 26 (2023), Article 23.4.8.
FORMULA
G.f.: x*y/((1 - x)^4*(1 - y)^3). - Stefano Spezia, May 21 2023
EXAMPLE
Array begins
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...
4, 12, 24, 40, 60, 84, 112, 144, 180, 220, ...
10, 30, 60, 100, 150, 210, 280, 360, 450, 550, ...
20, 60, 120, 200, 300, 420, 560, 720, 900, 1100, ...
35, 105, 210, 350, 525, 735, 980, 1260, 1575, 1925, ...
...
MATHEMATICA
A[n_, k_]:=Binomial[n+2, 3]Binomial[k+1, 2]; Table[A[n-k+1, k], {n, 10}, {k, n}]//Flatten (* Stefano Spezia, May 21 2023 *)
CROSSREFS
KEYWORD
AUTHOR
Gary W. Adamson, Mar 20 2005
EXTENSIONS
More terms from Stefano Spezia, May 21 2023
STATUS
approved