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Numbers k such that k^2 + 3 is prime.
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%I #26 Mar 16 2017 04:17:03

%S 0,2,4,8,10,14,22,28,38,50,52,62,64,70,74,76,92,94,106,112,122,130,

%T 134,140,146,154,158,160,172,178,218,230,242,244,248,256,274,286,298,

%U 304,316,322,326,340,350,356,364,368,398,406,416,424,430,434,440,458,470

%N Numbers k such that k^2 + 3 is prime.

%H Zak Seidov, <a href="/A049422/b049422.txt">Table of n, a(n) for n = 1..1000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Near-SquarePrime.html">Near-Square Prime</a>

%e 4^2 + 3 = 19, which is prime.

%t lst={};Do[If[PrimeQ[n^2+3], Print[n];AppendTo[lst, n]], {n, 10^5}];lst (* _Vladimir Joseph Stephan Orlovsky_, Aug 21 2008 *)

%o (PARI) isA049422(n) = isprime(n^2+3) \\ _Michael B. Porter_, Mar 19 2010

%Y Other sequences of the type "Numbers k such that k^2 + i is prime": A005574 (i=1), A067201 (i=2), this sequence (i=3), A007591 (i=4), A078402 (i=5), A114269 (i=6), A114270 (i=7), A114271 (i=8), A114272 (i=9), A114273 (i=10), A114274 (i=11), A114275 (i=12).

%K nonn,easy

%O 1,2

%A Paul Jobling (paul.jobling(AT)whitecross.com)