OFFSET
1,1
COMMENTS
a(n) is also the number of solutions to x^2*y = 4*n^3 in positive integers x and y.
LINKS
Felix Huber, Table of n, a(n) for n = 1..10000
Felix Huber, Maple programs
Eric Weisstein's World of Mathematics, Cone
Eric Weisstein's World of Mathematics, Sphere
EXAMPLE
a(3) = 4 counts the following right circular cones (r, h): (1, 108), (2, 27), (3, 12), (6, 3). These 4 cones have the same volume as a sphere with radius 3: (1/3)*Pi*1^2*108 = (1/3)*Pi*2^2*27 = (1/3)*Pi*3^2*12 = (1/3)*Pi*6^2*3 = (4/3)*Pi*3^3 = 36*Pi.
MAPLE
See Huber link.
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Huber, Sep 20 2024
STATUS
approved