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A064713 Numbers n such that prime(n)^2 - n is prime. 2

%I

%S 1,2,6,8,20,30,42,48,50,60,68,96,110,122,132,168,204,222,234,284,306,

%T 332,336,366,378,392,398,402,420,440,474,488,492,506,516,518,530,572,

%U 594,600,650,672,680,740,756,762,770,810,870,884,888,902,920,930,938

%N Numbers n such that prime(n)^2 - n is prime.

%H Harry J. Smith, <a href="/A064713/b064713.txt">Table of n, a(n) for n = 1..1000</a>

%e 6 is in the sequence because prime(6)^2 - 6 = 169 - 6 = 163 is a prime.

%p A064713:=n->`if`(isprime(ithprime(n)^2-n), n, NULL): seq(A064713(n), n=1..2*10^3); # _Wesley Ivan Hurt_, Jan 21 2017

%t Select[Range[1000],PrimeQ[Prime[#]^2-#]&] (* _Harvey P. Dale_, May 17 2013 *)

%o (PARI) { n=0; for (m=1, 10^9, if (isprime(prime(m)^2 - m), write("b064713.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 23 2009

%Y Cf. A064361.

%K easy,nonn

%O 1,2

%A _Robert G. Wilson v_, Oct 13 2001

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Last modified August 15 13:27 EDT 2020. Contains 336504 sequences. (Running on oeis4.)