A193320 G.f.: Sum_{n>=0} x^n*Product_{k=1..n} (1 - k*x) / (1 - (2*k-1)*x).

1, 1, 1, 2, 7, 31, 158, 907, 5785, 40496, 307993, 2524639, 22158860, 207111169, 2051807533, 21458470274, 236087173027, 2724128688979, 32876740543526, 414007923183559, 5428110627157597, 73954177162273736, 1045162786551967021, 15297280935680456227

Offset

0,4

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..200

Example

G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 7*x^4 + 31*x^5 + 158*x^6 + 907*x^7 +...
where
A(x) =  1 + x*(1-x)/(1-x) + x^2*(1-x)*(1-2*x)/((1-x)*(1-3*x)) + x^3*(1-x)*(1-2*x)*(1-3*x)/((1-x)*(1-3*x)*(1-5*x)) +...

Prog

(PARI) {a(n)=polcoeff(sum(m=0, n, x^m*prod(k=1, m, (1-k*x)/(1-(2*k-1)*x +x*O(x^n)))), n)}

Crossrefs

Sequence in context: A030945 A088554 A107595 * A030882 A273957 A221958

Adjacent sequences: A193317 A193318 A193319 * A193321 A193322 A193323

Keyword

nonn

Author

Paul D. Hanna, Jul 22 2011

Status

approved