OFFSET
1,11
COMMENTS
a(n) is the number of distinct rectangular cuboids each one having integer surface area 2*n and integer edge lengths x, y and z. - Felix Huber, Aug 08 2023
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
FORMULA
PROG
(PARI) a(n)=sum(i=1, n, sum(j=1, i, sum(k=1, j, if(i*j+j*k+k*i-n, 0, 1))))
(Haskell)
a066955 n = length [(x, y, z) | x <- [1 .. a000196 (div n 3)],
y <- [x .. div n x],
z <- [y .. div (n - x*y) (x + y)],
x * y + (x + y) * z == n]
-- Reinhard Zumkeller, Mar 23 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Mallows, Jan 26 2002
EXTENSIONS
More terms from Benoit Cloitre, Feb 02 2003
STATUS
approved