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A121101 Catapolyoctagons (see Cyvin et al. for precise definition). 1
1, 1, 3, 9, 39, 169, 819, 3969, 19719, 97969 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

REFERENCES

J. Brunvoll, S. J. Cyvin and B. N. Cyvin, Isomer enumeration of polygonal systems..., J. Molec. Struct. (Theochem), 364 (1996), 1-13.

S. J. Cyvin et al., Enumeration of tree-like octagonal systems: catapolyoctagons, ACH Models in Chem. 134 (1997), 55-70.

LINKS

Table of n, a(n) for n=1..10.

FORMULA

Empirical g.f.: x*(10*x^4-21*x^3+3*x^2+5*x-1) / ((x-1)*(5*x-1)*(5*x^2-1)). - Colin Barker, Aug 29 2013

CROSSREFS

Sequence in context: A149026 A149027 A180741 * A280066 A287063 A080635

Adjacent sequences:  A121098 A121099 A121100 * A121102 A121103 A121104

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 11 2006

STATUS

approved

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Last modified February 23 02:43 EST 2018. Contains 299473 sequences. (Running on oeis4.)