Search: id:A072346 Results 1-1 of 1 results found. %I A072346 %S A072346 1,1,1,3,2,15,6,105,24,945,120,10395,720,135135,5040,2027025,40320,34459425, %T A072346 362880,654729075,3628800,13749310575,39916800,316234143225,479001600, 7905853580625, %U A072346 6227020800,213458046676875,87178291200,6190283353629375,1307674368000 %N A072346 Volume of n-dimensional sphere of radius r is V_n*r^n = Pi^(n/2)*r^n/ (n/2)! = C_n*Pi^floor(n/2)*r^n; sequence gives denominator of C_n. %C A072346 Answer to question of how to extend the sequence 1, 2 r, Pi r^2, 4 Pi r^3 / 3, Pi^2 r^4 / 2, ... %C A072346 Surface area of n-dimensional sphere of radius r is n*V_n*r^(n-1). %D A072346 J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 9, Eq. 17. %H A072346 Eric Weisstein's World of Mathematics, Hypersphere %H A072346 Eric Weisstein's World of Mathematics, Ball %H A072346 Eric Weisstein's World of Mathematics, Four-Dimensional Geometry %F A072346 (n/2)! if n even, n!! if n odd. %e A072346 Sequence of C_n's begins 1, 2, 1, 4/3, 1/2, 8/15, 1/6, 16/105, 1/24, 32/945, 1/120, 64/10395, ... %t A072346 f[n_] := Pi^(n/2 - Floor[n/2])/(n/2)!; Table[ Denominator[ f[n]], {n, 0, 30} ] %Y A072346 Cf. A072345. %Y A072346 Cf. A001147. %Y A072346 Sequence in context: A033314 A070260 A142705 this_sequence A103236 A141235 A051917 %Y A072346 Adjacent sequences: A072343 A072344 A072345 this_sequence A072347 A072348 A072349 %K A072346 nonn,frac %O A072346 0,4 %A A072346 N. J. A. Sloane (njas(AT)research.att.com), Jul 31 2002 Search completed in 0.002 seconds