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%I #17 Sep 08 2022 08:45:23
%S 29,107,431,1487,1607,2141,5501,10139,10271,17579,22481,23057,27479,
%T 32369,36341,36929,38447,55931,57527,69827,75539,78539,79691,81047,
%U 81971,84179,86027,89561,93761,102059,112571,113147,118799,119687
%N Primes p such that p + 2, 18*p^2 + 1, and 18*(p+2)^2 + 1 are all primes.
%e a(1)=29 because 31, 18*29^2 + 1 = 15139, and 18*31^2 + 1 = 17299 are all primes.
%o (Magma) [p: p in PrimesUpTo(200000)| IsPrime(p+2) and IsPrime(18*p^2+1) and IsPrime(18*(p+2)^2+1)] // _Vincenzo Librandi_, Nov 13 2010
%Y Cf. A089001 (Numbers n such that 2*n^2 + 1 is prime),
%Y A090612 (Numbers k such that the k-th prime is of the form 2*k^2+1),
%Y A090698 (Primes of the form 2*n^2+1),
%Y A113541 (Numbers n such that 18*n^2+1 is a multiple of 19).
%K nonn
%O 1,1
%A _Zak Seidov_, Jan 19 2006
%E More terms from _Vincenzo Librandi_, Mar 27 2010