login
a(n) equals floor(Vc(n) - Vs(n)), where Vc(n) is the volume of the cube with side length n and Vs(n) is the volume of the sphere of diameter n.
1

%I #10 Sep 05 2014 02:50:45

%S 0,3,12,30,59,102,163,243,347,476,634,823,1046,1307,1607,1951,2340,

%T 2778,3267,3811,4411,5072,5796,6585,7443,8373,9377,10457,11618,12862,

%U 14192,15610,17120,18724,20425,22226,24131

%N a(n) equals floor(Vc(n) - Vs(n)), where Vc(n) is the volume of the cube with side length n and Vs(n) is the volume of the sphere of diameter n.

%F a(n) = floor(n^3*(1-Pi/6)).

%e a(7)=163 because 163=floor(7^3*(1-Pi/6)).

%t Table[Floor[n^3 (1-\[Pi]/6)],{n,40}] (* _Harvey P. Dale_, Apr 24 2011 *)

%Y Cf. A057672.

%K nonn

%O 1,2

%A seiringer.flor(AT)eudoramail.com, Oct 18 2000

%E Edited by _James A. Sellers_, Oct 20 2000