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Search: id:A122429
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| A122429 |
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Primes p such that q=4p^2+1, r=4q^2+1 and s=4r^2+1 are all primes. |
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| 13, 9833, 41647, 151607, 264757, 356123, 361223, 446863, 449093, 457813, 531383, 641057, 655927, 841697, 855947, 899263, 913687, 1052813, 1081757, 1379383, 1506493, 1575757, 1685087, 1821013, 1821377, 1981517, 2054233
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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13 is there because 13, 677, 1833317, and 13444204889957 are primes.
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MATHEMATICA
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Reap[Do[p=Prime[n]; q=4p^2+1; r=4q^2+1; s=4r^2+1; If[PrimeQ[{q, r, s}]=={True, True, True}, Sow[p]], {n, 15000}]][[2, 1]]
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CROSSREFS
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Cf. A052291 Primes p such that 4p^2 + 1 is also prime, A005574 Numbers n such that n^2 + 1 is prime.
Adjacent sequences: A122426 A122427 A122428 this_sequence A122430 A122431 A122432
Sequence in context: A032463 A060887 A020521 this_sequence A068731 A098562 A123921
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Oct 20 2006
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EXTENSIONS
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More terms from Don Reble (djr(AT)nk.ca), Oct 24 2006
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