On the powerfull part of $n^2+1$

J.-C. Puchta

E-mail: jcp@math.uni-freiburg.de

Abstract.
We show that $n^2+1$ is powerfull for $O(x^{2/5+\epsilon})$ integers $n\leq x$ at most,
thus answering a question of P. Ribenboim.

AMSclassification. 11N25, secondary 11D09, 11D25.

Keywords.