%I #7 Sep 06 2024 20:15:18

%S 1,1,1,1,3,6,12,27,63,155,401,1086,3067,8995,27340,85905,278484,

%T 929713,3191200,11245602,40631627,150342632,569071745,2201355133,

%U 8694775794,35035655103,143916920871,602218550964,2565370007348,11118142868084,48994958103507

%N Floor of ratio of volume of n-dimensional cube of side 2 to volume of n-dimensional ball of radius 1.

%D J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 9.

%F a(n) = floor(2^n * Gamma(n/2+1) / Pi^(n/2)).

%Y Cf. A057649, A072345, A072346.

%K nonn

%O 0,5

%A _N. J. A. Sloane_, Sep 06 2003