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

%I

%S 2,3,5,11,13,17,19,23,29,31,37,47,53,59,61,67,71,73,79,83,89,97,101,

%T 103,109,113,127,131,137,139,149,151,163,167,173,179,181,191,197,199,

%U 211,223,227,229,233,241,263,269,271,277,281,283,311,313,317,331,337

%N Primes p such that p^2 + 1 is squarefree.

%C Primes of the sequence A224718 generating squarefree.

%H Amiram Eldar, <a href="/A225856/b225856.txt">Table of n, a(n) for n = 1..10000</a>

%e 23 is a term since 23^2+1 = 530 = 2*5*53, is squarefree.

%e 43 is not a term since 43^2+1 = 1850 = 2*5^2*7, is not squarefree.

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

%Y Intersection of A000040 and A049533.

%Y Cf. A224718.

%K nonn

%O 1,1

%A _Rafael Parra Machio_, May 18 2013

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Last modified August 2 05:02 EDT 2021. Contains 346409 sequences. (Running on oeis4.)