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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

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 * A272387 A105902 A031909

Adjacent sequences:  A224715 A224716 A224717 * A224719 A224720 A224721

KEYWORD

nonn

AUTHOR

Zak Seidov, Apr 16 2013

STATUS

approved

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Last modified July 25 04:27 EDT 2017. Contains 289779 sequences.