OFFSET
1,2
COMMENTS
Not entirely symmetrical, the x^(n+1)+1 polynomials was added to remove zeros and make the triangle more symmetrical.
Row sums are:
{1, 3, 3, 4, 8, 26, 122, 722, 5042, 40322, 362882, 3628802}.
FORMULA
f(x,n)=x^(n+1)+1+A123125(x,n).
MATHEMATICA
lear[f, x, n, a] f[x_, n_] := f[x, n] = x^(n + 1) + (1 - x)^(n + 1)*Sum[k^n*x^k, {k, 0, Infinity}] + 1; Table[FullSimplify[ExpandAll[f[x, n]]], {n, 0, 10}]; a = Join[{{1}}, Table[CoefficientList[FullSimplify[ExpandAll[f[x, n]]], x], {n, 0, 10}]]; Flatten[a]
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Roger L. Bagula and Gary W. Adamson, Aug 25 2008
STATUS
approved