A203807 G.f.: exp( Sum_{n>=1} A000204(n)^7 * x^n/n ) where A000204 is the Lucas numbers.

1, 1, 1094, 6555, 809765, 10676072, 570282082, 11680775298, 427757608420, 10880625876510, 341910837405634, 9500984180929624, 282684350289144641, 8100555748749977985, 236841648715969283630, 6851665210550903756723, 199305150210062939465293

Offset

0,3

Comments

More generally, exp(Sum_{k>=1} A000204(k)^(2*n+1) * x^k/k) = Product_{k=0..n} 1/(1 - (-1)^(n-k)*A000204(2*k+1)*x - x^2)^binomial(2*n+1,n-k).

Links

G. C. Greubel, Table of n, a(n) for n = 0..680

Formula

G.f.: 1/( (1+x-x^2)^35 * (1-4*x-x^2)^21 * (1+11*x-x^2)^7 * (1-29*x-x^2) ).

G.f.: 1/Product_{n>=1} (1 - Lucas(n)*x^n + (-1)^n*x^(2*n))^A203857(n) where A203857(n) = (1/n)*Sum_{d|n} moebius(n/d)*Lucas(d)^6.

Example

G.f.: A(x) = 1 + x + 1094*x^2 + 6555*x^3 + 809765*x^4 + 10676072*x^5 + ...
where
log(A(x)) = x + 3^7*x^2/2 + 4^7*x^3/3 + 7^7*x^4/4 + 11^7*x^5/5 + 18^7*x^6/6 + 29^7*x^7/7 + 47^7*x^8/8 + ... + Lucas(n)^7*x^n/n + ...

Mathematica

CoefficientList[Series[1/((1 + x - x^2)^35*(1 - 4*x - x^2)^21*(1 + 11*x - x^2)^7*(1 - 29*x - x^2)), {x, 0, 50}], x] (* G. C. Greubel, Dec 25 2017 *)

Prog

(PARI) /* Subroutine used in PARI programs below: */
{Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}
(PARI) {a(n)=polcoeff(exp(sum(k=1, n, Lucas(k)^7*x^k/k)+x*O(x^n)), n)}
(PARI) {a(n, m=3)=polcoeff(prod(k=0, m, 1/(1 - (-1)^(m-k)*Lucas(2*k+1)*x - x^2+x*O(x^n))^binomial(2*m+1, m-k)), n)}

Crossrefs

Cf. A002571, A203803, A203804, A203805, A203806, A203808, A203809.

Cf. A203857, A203800.

Sequence in context: A259909 A124122 A163561 * A184470 A234722 A160370

Adjacent sequences: A203804 A203805 A203806 * A203808 A203809 A203810

Keyword

nonn

Author

Paul D. Hanna, Jan 06 2012

Status

approved