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A115272
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Primes p such that p+2, 18*p^2+1, 18*(p+2)^2+1 are all primes.
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0
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29, 107, 431, 1487, 1607, 2141, 5501, 10139, 10271, 17579, 22481, 23057, 27479, 32369, 36341, 36929, 38447, 55931, 57527, 69827, 75539, 78539, 79691, 81047, 81971, 84179, 86027, 89561, 93761, 102059, 112571, 113147, 118799, 119687
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Cf. A089001 Numbers n such that 2*n^2 + 1 is prime, A090612 n-th prime is of the form 2*k^2+1, A090698 Primes of the form 2*n^2+1, A113541 Numbers n such that 18*n^2+1 is multiple of 19.
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EXAMPLE
| a(1)=29 because 31, 18*29^2+1=15139, 18*31^2+1=17299 are all primes.
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PROG
| (MAGMA) [p: p in PrimesUpTo(200000)| IsPrime(p+2) and IsPrime(18*p^2+1) and IsPrime(18*(p+2)^2+1)] [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 13 2010]
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CROSSREFS
| Cf. A089001, A090612, A090698, A113541.
Sequence in context: A126554 A009406 A142176 * A138716 A142194 A139495
Adjacent sequences: A115269 A115270 A115271 * A115273 A115274 A115275
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KEYWORD
| nonn
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Jan 19 2006
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EXTENSIONS
| More terms from Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 27 2010
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