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Numbers n such that n^2 + 1 is a Chen prime.
1

%I #7 Dec 15 2017 17:36:55

%S 1,2,4,6,10,14,16,20,24,26,36,40,56,66,74,94,116,120,130,134,146,160,

%T 170,176,204,230,250,256,260,284,314,326,340,350,386,406,430,440,444,

%U 464,466,470,490,496,536,556,570,584,634,646,654,680,686,700,704,714

%N Numbers n such that n^2 + 1 is a Chen prime.

%H Harvey P. Dale, <a href="/A109807/b109807.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[800],PrimeQ[#^2+1]&&PrimeOmega[#^2+3]<3&] (* _Harvey P. Dale_, May 07 2015 *)

%o (PARI) is(n)=isprime(n^2+1) && bigomega(n^2+3)<3 \\ _Charles R Greathouse IV_, Aug 19 2015

%Y Subsequence of A005574.

%Y Cf. A005574, A109611.

%K nonn

%O 1,2

%A _Jason Earls_, Aug 16 2005