OFFSET
0,2
COMMENTS
Partial sums of A166696.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..500
FORMULA
G.f.: (1-3x+x^2-sqrt(1-14x+27x^2-14x^3+x^4))/(4x(1-x));
G.f.: 1/(1-x-3x/(1-x-2x/(1-x-3x/(1-x-2x/(1-x-3x/(1-x-2x/(1-.... (continued fraction);
a(n) = Sum_{k=0..n} C(n+k,2k)*A103210(k).
Conjecture: (n+1)*a(n) + 3*(-5*n+2)*a(n-1) + (41*n-61)*a(n-2) + (-41*n+103)*a(n-3) + 3*(5*n-18)*a(n-4) + (-n+5)*a(n-5) = 0. - R. J. Mathar, Feb 10 2015
MAPLE
MATHEMATICA
CoefficientList[Series[(1 - 3*t + t^2 - Sqrt[1 - 14*t + 27*t^2 - 14*t^3 + t^4])/(4*t*(1 - t)), {t, 0, 50}], t] (* G. C. Greubel, May 23 2016 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Oct 18 2009
STATUS
approved