A208832 G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n * Product_{k=1..n} (1 - k*x)/(1 + k*x).

1, 1, 3, 17, 153, 1961, 33267, 709937, 18375001, 561358441, 19825203355, 796240555449, 35891569819217, 1796230428709665, 98908294526888507, 5946867742763879145, 387872935717894524737, 27288493956110862779089, 2060691818131992283884307, 166303287155431671466946881

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Example

 G.f.: 1/(1-x) = 1 + 1*x*(1-x)/(1+x) + 3*x^2*(1-x)*(1-2*x)/((1+x)*(1+2*x)) + 17*x^3*(1-x)*(1-2*x)*(1-3*x)/((1+x)*(1+2*x)*(1+3*x)) + 153*x^4*(1-x)*(1-2*x)*(1-3*x)*(1-4*x)/((1+x)*(1+2*x)*(1+3*x)*(1+4*x)) +...

Prog

 (PARI) {a(n)=if(n==0, 1, 1-polcoeff(sum(k=0, n-1, a(k)*x^k*prod(j=1, k, (1-j*x)/(1+j*x+x*O(x^n)))), n))}
for(n=0, 25, print1(a(n), ", "))

Crossrefs

Cf. A208833.

Sequence in context: A364630 A318987 A353258 * A135751 A368444 A168441

Adjacent sequences: A208829 A208830 A208831 * A208833 A208834 A208835

Keyword

nonn

Author

Paul D. Hanna, Mar 01 2012

Status

approved