A224718 Primes p such that p^2 + 1 is not squarefree.

7, 41, 43, 107, 157, 193, 239, 251, 257, 293, 307, 443, 457, 557, 577, 593, 607, 643, 743, 757, 829, 857, 907, 1093, 1193, 1303, 1307, 1451, 1483, 1493, 1543, 1607, 1657, 1693, 1723, 1789, 1907, 1993, 2143, 2207, 2243, 2267, 2293, 2309, 2357, 2393, 2543

Offset: 1

Author

Zak Seidov, Apr 16 2013

Keywords

• nonn

Examples

			7^2 + 1 = 50 = 2*5^2, 41^2 + 1 = 1681 = 2*29^2.
		

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A039787.

Programs

Mathematica

Select[Prime[Range[300]], ! SquareFreeQ[#^2 + 1] &]