On a conjecture of Helleseth
  We are concern about a conjecture proposed in the middle of the seventies by Hellesseth in the framework of maximal sequences and theirs cross-correlations. The conjecture claims the existence of a zero outphase Fourier coefficient. We give some divisibility properties in this direction. 
Yves Aubry (IML, IMATH), Philippe Langevin (IMATH)
math.NT