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A140765
Array T(n,k) = binomial(k+2, k-1) + n*binomial(k+2, k) read by antidiagonals.
1
0, 1, 1, 2, 4, 4, 3, 7, 10, 10, 4, 10, 16, 20, 20, 5, 13, 22, 30, 35, 35, 6, 16, 28, 40, 50, 56, 56, 7, 19, 34, 50, 65, 77, 84, 84, 8, 22, 40, 60, 80, 98, 112, 120, 120, 9, 25, 46, 70, 95, 119, 140, 156, 165, 165, 10, 28, 52, 80, 110, 140, 168, 192, 210, 220, 220, 11, 31, 58
OFFSET
0,4
LINKS
D. A. Sardelis, T. M. Valahas, On Multidimensional Pythagorean Numbers, arxiv:0805.4070 [math.GM], 2008, Table 6, eq 12.
FORMULA
T(n,k) = binomial(k+2, 3) + n*binomial(k+2, 2).
EXAMPLE
The array starts in row n=0 with columns k >= 0 as
0, 1, 4, 10, 20, 35, 56, 84, 120, 165, 220, ...
1, 4, 10, 20, 35, 56, 84, 120, 165, 220, 286, ...
2, 7, 16, 30, 50, 77, 112, 156, 210, 275, 352, ...
3, 10, 22, 40, 65, 98, 140, 192, 255, 330, 418, ...
4, 13, 28, 50, 80, 119, 168, 228, 300, 385, 484, ...
5, 16, 34, 60, 95, 140, 196, 264, 345, 440, 550, ...
...
MAPLE
A140765 := proc(n, k) binomial(k+2, k-1)+n*binomial(k+2, k) ; end proc:
# R. J. Mathar, Aug 31 2011
MATHEMATICA
T[n_, k_] := Binomial[k + 2, k - 1] + n Binomial[k + 2, k];
Table[T[n - k, k], {n, 0, 11}, {k, 0, n}] // Flatten (* Jean-François Alcover, Dec 03 2017 *)
CROSSREFS
Sequence in context: A098217 A151846 A131118 * A097541 A151819 A079560
KEYWORD
nonn,tabl,easy
AUTHOR
Gary W. Adamson, May 28 2008
EXTENSIONS
Definition substantiated by R. J. Mathar, Aug 31 2011
STATUS
approved