OFFSET
1,2
COMMENTS
EXAMPLE
PROG
(PARI) a(n, L=10^9)={n=if(n>0, A020898[n], -n); for(b=1, L, for(a=1, b, (a^3+b^3)%n&&next; ispower((a^3+b^3)/n, 3)&&return(b)))}
CROSSREFS
KEYWORD
nonn,more
AUTHOR
M. F. Hasler, Jan 27 2015
STATUS
approved