

A243933


Rounded down ratio of a minimum intersection area with a unit circle area in nsymmetrical unit circles intersect in a single point.


1



17, 5, 77, 17, 210, 40, 445, 77, 812, 133, 1339, 210, 2056, 313, 2991, 445, 4175, 610, 5636, 812, 7403, 1054, 9506, 1339, 11973, 1672, 14835, 2056, 18120, 2494, 21856, 2991, 26075, 3550, 30804, 4175, 36073, 4869
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

3,1


COMMENTS

Refer to construction rule in article "CircleCircle Intersection" in MathWorld.
For n > 4, the intersected areas appearing at many sizes. In this case the minimum areas are considered. See illustration in links.


LINKS

Table of n, a(n) for n=3..40.
Kival Ngaokrajang, Illustration of initial terms
Eric Weisstein's World of Mathematics, CircleCircle Intersection


FORMULA

For n > 2, a(n) = floor(Pi/area), where area = 2*acos(cd/2)(1/2)*cd*(4cd^2)^(1/2), cd = 2*sin(((ang*360/n)*Pi/180)/2), ang = floor((n1)/2).


PROG

(PARI) {for (n=3, 100, ang=floor((n1)/2); cd=2*sin(((ang*360/n)*Pi/180)/2); area=2*acos(cd/2)(1/2)*cd*(4cd^2)^(1/2); print1(floor(Pi/area), ", "))}


CROSSREFS

Sequence in context: A297982 A298631 A338559 * A145965 A040276 A166211
Adjacent sequences: A243930 A243931 A243932 * A243934 A243935 A243936


KEYWORD

nonn


AUTHOR

Kival Ngaokrajang, Jun 15 2014


STATUS

approved



