

A200257


Decimal expansion of the circumradius R of cyclic pentagon with sides 2, 3, 5, 7, and 11.


3



5, 5, 0, 6, 2, 9, 9, 6, 3, 8, 6, 6, 8, 1, 3, 1, 8, 1, 9, 8, 8, 4, 3, 9, 5, 0, 6, 3, 3, 1, 3, 1, 8, 8, 1, 6, 6, 3, 2, 5, 3, 5, 3, 9, 0, 5, 5, 1, 8, 2, 7, 9, 2, 0, 0, 0, 3, 9, 6, 8, 0, 3, 8, 8, 6, 5, 0, 1, 1, 9, 7, 7, 6, 2, 9, 3, 6, 2, 9, 1, 1, 1, 8, 8, 9
(list;
constant;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Note that for cyclic polygon R does not depend on order of sides.


LINKS

Table of n, a(n) for n=1..85.
Ralph H. Buchholz and James A. MacDougall, Cyclic polygons with rational Sides and Area, Journal of Number Theory, Volume 128, Issue 1, January 2008, Pages 1748.
Zak Seidov, Figure showing polygon


EXAMPLE

R = 5.5062996386681...


MATHEMATICA

nn=5; L=Sum[Prime[n], {n, nn}]; RealDigits[Re[FindRoot[Sum[ArcSin[Prime[n]/2/R], {n, nn}] == Pi, {R, L/2/Pi}][[1, 2]]]]


CROSSREFS

Sequence in context: A065936 A299625 A021649 * A236023 A200516 A233383
Adjacent sequences: A200254 A200255 A200256 * A200258 A200259 A200260


KEYWORD

nonn,cons


AUTHOR

Zak Seidov, Nov 15 2011


STATUS

approved



