@article{Grytczuk:2005,
  author  = "A. Grytczuk and B. Mędryk",
  title   = "On a result of Flammenkamp-Luca concerning noncototient sequence",
  journal = "Tsukuba Journal of Mathematics",
  volume  = "Vol. 29",
  number  = "no 2",
  pages   = "533--538",
  year    = "2005",
}