OFFSET
0,4
COMMENTS
Row sums are:
{1, 2, 6, 36, 300, 3240, 42840, 670320, 12111120, 248119200, 5683154400,...}.
The first column is A001147:
{1, 1, 3, 15, 105, 945, 10395, 135135, 2027025, 34459425, 654729075,...}.
FORMULA
p(x,n)=Sum[Binomial[n, m]*p[x, m]*p[x, n - m - 1], {m, 0, n - 1}].
EXAMPLE
{1},
{1, 1},
{3, 3},
{15, 18, 3},
{105, 150, 45},
{945, 1575, 675, 45},
{10395, 19845, 11025, 1575},
{135135, 291060, 198450, 44100, 1575},
{2027025, 4864860, 3929310, 1190700, 99225},
{34459425, 91216125, 85135050, 32744250, 4465125, 99225},
{654729075, 1895268375, 2006754750, 936485550, 180093375, 9823275}
MATHEMATICA
p[x, 0] = 1;
p[x, 1] = x + 1;
p[x_, n_] := Sum[Binomial[n, m]*p[x, m]*p[x, n - m - 1], {m, 0, n - 1}];
Table[ExpandAll[p[x, n]], {n, 0, 10}];
Table[CoefficientList[ExpandAll[p[x, n]], x], {n, 0, 10}];
Flatten[%]
CROSSREFS
KEYWORD
AUTHOR
Roger L. Bagula, Mar 02 2009
STATUS
approved