1,1

Primes of the sequence A224718 generating squarefree.

Table of n, a(n) for n=1..57.

23^2+1 = 530 = 2*5*53, is squarefree; 43^2+1 = 1850 = 2*5^2*7, is not squarefree.

Select[Prime[Range[100]], SquareFreeQ[#^2+1]&]

Cf. A224718.

Sequence in context: A187921 A275059 A072538 * A322173 A216509 A075237

Adjacent sequences: A225853 A225854 A225855 * A225857 A225858 A225859

nonn

Rafael Parra Machio, May 18 2013

approved