A121094 Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition).

0, 1, 2, 2, 8, 9, 26, 28, 88, 89, 292, 297, 994, 1001, 3418, 3430, 11920, 11934, 41944, 41990, 149184, 149221, 534756, 534888, 1931394, 1931540, 7019976, 7020391, 25662396, 25662825, 94285650, 94287120, 347992480, 347993868

Offset

0,3

Links

Table of n, a(n) for n=0..33.

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

Maple

U0 := (1-sqrt(1-4*x))/2/x ;
V0 := 1+x*subs(x=x^2, U0) ;
Mb := ( subs(x=x^2, U0)^3 -subs(x=x^4, U0)*subs(x=x^2, V0) -subs(x=x^6, U0) +subs(x=x^6, V0) )/2 ; # (20)
Ma := ( subs(x=x^2, U0)^2*V0^2 -subs(x=x^3, V0)^2 -subs(x=x^4, U0)*subs(x=x^2, V0) +subs(x=x^6, V0) )/2 ; # (21)
M := Mb+Ma ;
taylor(%, x=0, 40) ;
gfun[seriestolist](%) ; # R. J. Mathar, Jul 26 2019

Crossrefs

Sequence in context: A131659 A137726 A121098 * A029595 A343447 A320138

Adjacent sequences: A121091 A121092 A121093 * A121095 A121096 A121097

Keyword

nonn

Author

N. J. A. Sloane, Aug 11 2006

Status

approved