OFFSET
0,3
REFERENCES
Brass, Peter; Moser, William; Pach, Janos (2005), "3.3 Levi-Hadwiger Covering Problem and Illumination", Research Problems in Discrete Geometry, Springer-Verlag, pp. 136-142 .
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 0..250
Hugo Hadwiger, Über eine Klassifikation der Streckenkomplexe, Vierteljschr. Naturforsch. ges. Zürich 88: 133-143 (1943).
A. V. Kostochka, Lower bound of the Hadwiger number of graphs by their average degree, Combinatorica 4 (4) (1984), 307-316.
Wikipedia, Hadwiger conjecture (combinatorial geometry).
FORMULA
a(n) = floor((4^n)*(5*n*log(n))).
EXAMPLE
a(1) = (4^1) * (5 * 1 * log(1)) = 0.
a(2) = floor ((4^2) * (5 * 2 * log(2))) = floor(110.903549) = 110.
a(3) = floor(1054.6678) = 1054.
MATHEMATICA
Table[If[n==0, 0, Floor[(4^n)*(5*n*Log[n])]], {n, 0, 30}] (* G. C. Greubel, Jun 12 2018 *)
PROG
(PARI) for(n=0, 30, print1(if(n==0, 0, floor((4^n)*(5*n*log(n)))) , ", ")) \\ G. C. Greubel, Jun 12 2018
(Magma) [0] cat [ Floor((4^n)*(5*n*Log(n))) : n in [1..30]]; // G. C. Greubel, Jun 12 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 14 2009
EXTENSIONS
a(7)-a(22) from Nathaniel Johnston, Apr 26 2011
STATUS
approved