OFFSET
1,8
COMMENTS
An irregular triangle with only the nonzero coefficients is given by A290262.
EXAMPLE
Triangle begins:
1;
1, 1;
1, 1, 0;
1, 2, 2, 1;
1, 2, 2, 1, 0;
1, 3, 4, 2, 0, 0;
1, 3, 5, 5, 3, 1, 0;
1, 4, 9, 13, 13, 9, 4, 1;
1, 4, 9, 13, 13, 9, 4, 1, 0;
1, 5, 14, 25, 30, 24, 12, 3, 0, 0;
1, 5, 15, 30, 42, 42, 30, 15, 5, 1, 0;
1, 6, 21, 48, 75, 81, 60, 30, 10, 2, 0, 0;
MATHEMATICA
nn=12; Solve[Table[Expand[SeriesCoefficient[Product[1/(1+c[k]x^k), {k, n}], {x, 0, n}]]==-t, {n, nn}], Table[c[n], {n, nn}]][[1, All, 2]]
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gus Wiseman, Jul 27 2017
STATUS
approved