OFFSET
0,3
COMMENTS
FORMULA
Number triangle where column k has g.f. (1+x+x^2)(k+1)x^k.
EXAMPLE
Triangle begins
1;
1, 2;
1, 2, 3;
0, 2, 3, 4;
0, 0, 3, 4, 5;
0, 0, 0, 4, 5, 6;
0, 0, 0, 0, 5, 6, 7;
0, 0, 0, 0, 0, 6, 7, 8;
MATHEMATICA
Table[If[#<(n-2), 0, #]&/@Range[n], {n, 15}]//Flatten (* Harvey P. Dale, Oct 14 2022 *)
CROSSREFS
KEYWORD
AUTHOR
Paul Barry, Oct 14 2005
STATUS
approved