A225856 Primes p such that p^2 + 1 is squarefree.

2, 3, 5, 11, 13, 17, 19, 23, 29, 31, 37, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 109, 113, 127, 131, 137, 139, 149, 151, 163, 167, 173, 179, 181, 191, 197, 199, 211, 223, 227, 229, 233, 241, 263, 269, 271, 277, 281, 283, 311, 313, 317, 331, 337

Offset

1,1

Comments

Primes of the sequence A224718 generating squarefree.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

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

Mathematica

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

Crossrefs

Intersection of A000040 and A049533.

Cf. A224718.

Sequence in context: A187921 A275059 A072538 * A322173 A216509 A075237

Adjacent sequences: A225853 A225854 A225855 * A225857 A225858 A225859

Keyword

nonn

Author

Rafael Parra Machio, May 18 2013

Status

approved