OFFSET
1,1
COMMENTS
Volume of the 9-dimensional unit sphere.
More generally, the ordinary generation function for the volume of the n-dimensional unit sphere is exp(Pi*x^2)*(erf(sqrt(Pi)*x) + 1) = 1 + 2*x + Pi*x^2 + (4*Pi/3)*x^3 + (Pi^2/2)*x^4 + ...
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
Ilya Gutkovskiy, Volume of the n-dimensional unit sphere
Eric Weisstein's World of Mathematics, Hypersphere
EXAMPLE
3.2985089027387068693821065037445117...
MATHEMATICA
RealDigits[(32 Pi^4)/945, 10, 120][[1]]
PROG
(PARI) (32*Pi^4)/945 \\ G. C. Greubel, Apr 09 2017
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Aug 16 2016
STATUS
approved