A121092 Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition).

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

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: A343548 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