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A063812 Growth series for fundamental group of orientable closed surface of genus 2. 0
1, 8, 56, 392, 2736, 19096, 133288, 930328, 6493536, 45323816, 316352792, 2208090536, 15412109328, 107573992120, 750848799112, 5240801312824, 36579932515008, 255321921769544, 1782105084785144, 12438800833105352 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 160, Sigma(Gamma_2, S_2; z).

LINKS

Table of n, a(n) for n=0..19.

FORMULA

G.f.: (1+x)^2*(x^2+1)/(x^4-6*x^3-6*x^2-6*x+1).

CROSSREFS

Sequence in context: A010556 A010575 A162949 * A234274 A163347 A163924

Adjacent sequences:  A063809 A063810 A063811 * A063813 A063814 A063815

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 21 2001

STATUS

approved

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Last modified December 11 13:58 EST 2018. Contains 318049 sequences. (Running on oeis4.)