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A175600
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Primes of form 4k+1 where k is a Pythagorean prime.
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2
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53, 149, 293, 389, 773, 1109, 1493, 1637, 1733, 2309, 2693, 2837, 3413, 3989, 4133, 4373, 4517, 5189, 5717, 5813, 6197, 6389, 7013, 7109, 8069, 8117, 9173, 9749, 10709, 10853, 11813, 12149, 12197, 12437, 12917, 13829, 13877, 14549, 15077, 15173
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OFFSET
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1,1
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COMMENTS
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"Double-Pythagorean" primes: primes of form 4k+1 with k prime of form 4m+1.
All terms are congruent to 5 modulo 48. - Zak Seidov, Jun 05 2014
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LINKS
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Table of n, a(n) for n=1..40.
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EXAMPLE
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53 = A002144(7) = 4*13 + 1, 13 = A002144(2);
149 = A002144(16) = 4*37 + 1, 37 = A002144(5).
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MATHEMATICA
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se=Select[Range[5, 100000, 4], PrimeQ]; (* se=A002144 *)
se2=Select[se, MemberQ[se, (#-1)/4]&]
(* (se2-1)/4 = intersection (A005098, A002144) *)
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CROSSREFS
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Cf. A002144 (Pythagorean primes: primes of form 4n+1), A005098 (Numbers n such that 4n+1 is prime).
Sequence in context: A161611 A251076 A142043 * A142417 A217718 A044385
Adjacent sequences: A175597 A175598 A175599 * A175601 A175602 A175603
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov, Jul 22 2010
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STATUS
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approved
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