OFFSET
1,3
LINKS
Robert Gerbicz, May 09 2008, Table of n, a(n) for n = 1..40
EXAMPLE
a(2)=1 because the only way to express 2^3 = 8 as a sum of two squares is 8 = 2^2 + 2^2.
a(3)=2 because 3^3 = 27 = 1^2 + 1^2 + 5^2 = 3^2 + 3^2 + 3^2.
PROG
(PARI) a(i, n, k)=local(s, j); if(k==1, if(issquare(n), return(1), return(0)), s=0; for(j=ceil(sqrt(n/k)), min(i, floor(sqrt(n-k+1))), s+=a(j, n-j^2, k-1)); return(s)) for(n=1, 50, m=n^3; k=n; print1(a(m, m, k)", ") ) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Dec 16 2007
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Sep 11 2007
EXTENSIONS
2 more terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Dec 16 2007
More terms from Robert Gerbicz, May 09 2008
STATUS
approved