OFFSET
1,2
COMMENTS
The Hankel transform of this sequence is 42^C(n+1,2) .
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..700
FORMULA
a(n) = Sum_{k=0..n} A086810(n,k)*6^k.
From Vaclav Kotesovec, Aug 20 2013: (Start)
G.f.: (x-13-sqrt(x^2-26*x+1))/14.
Recurrence: n*a(n) = 13*(2*n-3)*a(n-1) - (n-3)*a(n-2).
a(n) ~ sqrt(13*sqrt(42)-84)*(13+2*sqrt(42))^n/(14*sqrt(Pi)*n^(3/2)). (End)
G.f.: x/(1 - 6*x/(1 - 7*x/(1 - 6*x/(1 - 7*x/(1 - 6*x/(1 - ...)))))), a continued fraction. - Ilya Gutkovskiy, Apr 20 2017
MATHEMATICA
Rest[CoefficientList[InverseSeries[Series[x*(1-7*x)/(1-x), {x, 0, 20}], x], x]] (* Vaclav Kotesovec, Aug 20 2013 *)
PROG
(PARI) Vec(serreverse(x*(1-7*x)/(1-x)+O(x^66))) /* Joerg Arndt, Feb 06 2013 */
CROSSREFS
KEYWORD
nonn
AUTHOR
Philippe Deléham, Oct 29 2007
EXTENSIONS
More terms from Philippe Deléham, Feb 06 2013
Offset corrected, Joerg Arndt, Feb 15 2013
STATUS
approved