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A224718
Primes p such that p^2 + 1 is not squarefree.
3
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
1,1
EXAMPLE
7^2 + 1 = 50 = 2*5^2, 41^2 + 1 = 1681 = 2*29^2.
MATHEMATICA
Select[Prime[Range[300]], ! SquareFreeQ[#^2 + 1] &]
CROSSREFS
Cf. A039787.
Sequence in context: A023251 A073501 A080666 * A374234 A272387 A338771
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 16 2013
STATUS
approved