OFFSET
1,2
COMMENTS
Marshall Hall, Jr. conjectured that there exists a constant c > 0 such that for any integers x and y with y^2 != x^3 the relation abs(y^2 - x^3) > c*sqrt(abs(x)) holds.
LINKS
Wikipedia, Hall's conjecture.
PROG
(PARI) nearestcube(n) = my(x=n-1, y=n+1); while(!ispower(x, 3) && !ispower(y, 3), x--; y++); if(ispower(x, 3), return(x)); if(ispower(y, 3), return(y))
a(n) = abs(n^2 - nearestcube(n^2))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Jun 04 2016
STATUS
approved