OFFSET
3,1
REFERENCES
M. S. Klamkin et al., The kissing number of the square, Math. Magazine, 68 (1995), 128-133.
L. Zhao and J. Xu, The kissing number of the regular pentagon, Discrete Math., 252 (2002), 293-298.
LINKS
FORMULA
a(n) = 6 for n >= 5.
G.f.: 2*x^3*(6-2*x-x^2)/(1-x). - Elmo R. Oliveira, Jul 16 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 26 2002
STATUS
approved