OFFSET
0,1
REFERENCES
S. J. Cyvin and I. Gutman, Kekulé structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (see p. 313).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..550
FORMULA
a(n) = 9*binomial(2n, n)^3 - 12*binomial(2n, n)^2 + 6*binomial(2n, n) - 1.
MAPLE
a:=n->9*binomial(2*n, n)^3-12*binomial(2*n, n)^2+6*binomial(2*n, n)-1; seq(a(n), n=0..16);
MATHEMATICA
Table[9*Binomial[2*n, n]^3 - 12*Binomial[2*n, n]^2 + 6*Binomial[2*n, n] - 1, {n, 0, 50}] (* G. C. Greubel, Sep 06 2017 *)
PROG
(PARI) for(n=0, 25, print1(9*binomial(2n, n)^3 - 12*binomial(2n, n)^2 + 6*binomial(2n, n) - 1, ", ")) \\ G. C. Greubel, Sep 06 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Aug 03 2005
STATUS
approved