The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A121094 Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition). 0
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS 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 A320138 A325102 Adjacent sequences:  A121091 A121092 A121093 * A121095 A121096 A121097 KEYWORD nonn AUTHOR N. J. A. Sloane, Aug 11 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 17 18:00 EST 2020. Contains 330987 sequences. (Running on oeis4.)