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%I #10 Dec 27 2019 16:26:43
%S 1,2,6,36,156,210,270,306,576,690,936,966,2136,2310,2550,2706,2850,
%T 3390,3966,4026,4176,4260,4566,4590,5226,5430,5850,6120,6216,6360,
%U 6420,6546,7410,7536,8940,9126,9240,9276,9900,10530,10836,11286,11586,11886,12390,13680
%N Numbers n such that n+1, 2n+1 and n^2+1 are primes.
%C Intersection of A070689 and b(n)=A005382(n)-1.
%H Harvey P. Dale, <a href="/A236692/b236692.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range[14000],AllTrue[{#+1,2#+1,#^2+1},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 27 2019 *)
%o (Python)
%o import sympy
%o from sympy import isprime
%o for n in range(100000):
%o if isprime(n+1) and isprime(n*2+1) and isprime(n*n+1): print str(n)+',',
%o (PARI)
%o s=[]; for(n=1, 15000, if(isprime(n+1)&&isprime(2*n+1)&&isprime(n^2+1), s=concat(s, n))); s \\ _Colin Barker_, Jan 30 2014
%Y Cf. A005382, A070689.
%K nonn
%O 1,2
%A _Alex Ratushnyak_, Jan 30 2014
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