OFFSET
1,1
COMMENTS
a(n) is the ceiling of the area of a square with diagonal n times the circumference of a circle with diameter n. - Wesley Ivan Hurt, Oct 03 2014
a(n) is also the ceiling of the volume of a cylinder with radius n and height n/2. Equivalently, a(n) is the ceiling of the volume of a cylinder with diameter n and height 2*n. - Derek Orr, Oct 03 2014
MAPLE
MATHEMATICA
Table[Ceiling[n^3*(Pi/2)], {n, 40}] (* Wesley Ivan Hurt, Oct 03 2014 *)
PROG
(Java) int a(int n) {return (int) Math.ceil(Math.pow(n, 3)*Math.PI/(2)); }
(PARI) vector(100, n, ceil(n^3*Pi/2)) \\ Derek Orr, Oct 03 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Juliann Barbella, Oct 03 2014
STATUS
approved