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A121092 Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition). 1
1, 1, 4, 11, 41, 141, 533, 1952, 7320, 27287, 102322, 383616, 1442145, 5428213, 20472232, 77333718, 292638204, 1109160702, 4210704579, 16009469632, 60959141474, 232440067211, 887498464664, 3392984209344, 12987589660706 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..24.

B. N. Cyvin, E. Brendsdal, J. Brunvoll and S. J. Cyvin, Isomers of polyenes attached to benzene, Croatica Chemica Acta, 68 (1995), 63-73.

MAPLE

( 12*(1-x^2-2*x^3) -(1-4*x+3*x^2)*sqrt(1-4*x) -(7+6*x)*(1-x^2)*sqrt(1-4*x^2) -2*sqrt(1-4*x^3) -2*sqrt(1-4*x^6) )/24/x^6 ;

taylor(%, x=0, 31) ;

gfun[seriestolist](%) ; # R. J. Mathar, Jul 25 2019

CROSSREFS

Sequence in context: A152532 A121096 A047091 * A281346 A030981 A151455

Adjacent sequences:  A121089 A121090 A121091 * A121093 A121094 A121095

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 11 2006

STATUS

approved

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Last modified December 8 14:38 EST 2019. Contains 329865 sequences. (Running on oeis4.)