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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A097632 2^n * Lucas(n). 0
2, 12, 64, 672, 8448, 138240, 2672640, 60641280, 1568931840, 45705461760, 1478924697600, 52646746521600, 2044394156851200, 86005817907609600, 3896481847600742400, 189139342470414336000, 9793081532749971456000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Number of possible well-colored cycles on n nodes. Well-colored means, each green vertex has at least a red child, each red vertex has no red child.

LINKS

Table of n, a(n) for n=1..17.

C. Banderier, J.-M. Le Bars and V. Ravelomanana, Generating functions for kernels of digraphs

FORMULA

E.g.f.: -log(1-2x-4x^2). Contrary to b(n) = 2^n*Fib(n), there seems to be no rational o.g.f. for the sequence.

CROSSREFS

Equals A000079(n) * A000204(n).

Sequence in context: A226226 A126737 A345697 * A076804 A190153 A334772

Adjacent sequences:  A097629 A097630 A097631 * A097633 A097634 A097635

KEYWORD

nonn

AUTHOR

Ralf Stephan, Aug 17 2004

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 3 03:52 EDT 2021. Contains 346435 sequences. (Running on oeis4.)