|
| |
|
|
A124835
|
|
Row sums of triangle A124834.
|
|
2
| |
|
|
1, 2, 4, 9, 25, 91, 444, 2920, 25996, 314752, 5201874, 117719942, 3658433597, 156505343943, 9234365056453, 752841451059559, 84938741035295776, 13279814559055121447, 2880581923860441220144, 867855593621657824023139
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
FORMULA
| G.f.: A(x) = Sum_{k>=0} x^n * Product_{k=0..n} 1/(1 - binomial(n,k)*x).
|
|
|
EXAMPLE
| A(x) = 1/(1-x) + x/((1-x)(1-x)) + x^2/((1-x)(1-2x)(1-x)) + x^3/((1-x)(1-3x)(1-3x)(1-x)) + x^4/((1-x)(1-4x)(1-6x)(1-4x)(1-x)) +...
|
|
|
PROG
| (PARI) {a(n)=sum(k=0, n, polcoeff(1/prod(j=0, k, 1-binomial(k, j)*x +x*O(x^n)), n-k))}
|
|
|
CROSSREFS
| Cf. A124834, A124836.
Sequence in context: A173496 A173311 A127055 * A125799 A188669 A087378
Adjacent sequences: A124832 A124833 A124834 * A124836 A124837 A124838
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Paul D. Hanna (pauldhanna(AT)juno.com), Nov 09 2006
|
| |
|
|
