Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A110695
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A110695 Kekule numbers for certain benzenoids of trigonal symmetry. +0
1
1, 9, 341, 14859, 671509, 31816259, 1575219491, 80813149559, 4262996933909, 229858972288659, 12613108252122091, 702092835479959559, 39548041458039952291, 2250117073947022121799, 129122621276859925669799 (list; graph; listen)
OFFSET

0,2

REFERENCES

S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p 313).

FORMULA

a(n)=[2binomial(2n, n)-1][binomial(2n, n)^2-binomial(2n, n)+1].

MAPLE

a:=n->(2*binomial(2*n, n)-1)*(binomial(2*n, n)^2-binomial(2*n, n)+1); seq(a(n), n=0..16);

CROSSREFS

Sequence in context: A090085 A098650 A098652 this_sequence A157589 A055601 A012812

Adjacent sequences: A110692 A110693 A110694 this_sequence A110696 A110697 A110698

KEYWORD

nonn

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 03 2005

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


AT&T Labs Research