OFFSET
0,3
COMMENTS
REFERENCES
A. Hora, N. Obata, Quantum Probability and Spectral Analysis of Graphs, Springer, 2007, p. 122
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..500
FORMULA
G.f.: 1/(1-x+x*c(-2x/(1-x))), c(x) the g.f. of A000108.
G.f.: 1/(1-2x^2/(1-3x-4x^2/(1-3x-4x^2/(1-3x-4x^2/(1-... (continued fraction).
Conjecture: n*a(n) + 2*(2*n-5)*a(n-1) + (34-19*n)*a(n-2) + 14*(n-2)*a(n-3)=0. - R. J. Mathar, Nov 14 2011
MATHEMATICA
CoefficientList[Series[(3 (1 - x) - Sqrt[1 + 6 x - 7 x^2])/(2 (1 - x) (1 - 2 x)), {x, 0, 50}], x](* G. C. Greubel, Apr 24 2016 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 06 2009
STATUS
approved