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A113158
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Primes such that the sum of the predecessor and successor primes is divisible by 43.
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15
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521, 821, 859, 1069, 1459, 1549, 2203, 2411, 2539, 2837, 2969, 3011, 3089, 3359, 3613, 3823, 4259, 4339, 4561, 4643, 4783, 5503, 5557, 6067, 6619, 6967, 7481, 7699, 7741, 8263, 8779, 9419, 10103, 12041, 12379, 12641, 12899, 13417, 13721, 13759
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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a(n) = prime(i) is in this sequence iff prime(i-1)+prime(i+1) = 0 mod 43. a(n) = A000040(i) is in this sequence iff A000040(i-1)+A000040(i+1) = 0 mod 43.
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EXAMPLE
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a(1) = 521 since prevprime(521) + nextprime(521) = 509 + 523 = 1032 = 43 * 24.
a(2) = 821 since prevprime(821) + nextprime(821) = 811 + 823 = 1634 = 43 * 38.
a(3) = 859 since prevprime(859) + nextprime(859) = 857 + 863 = 1720 = 43 * 40.
a(4) = 1069 since prevprime(1069)+nextprime(1069) = 1063+1087 = 2150 = 43 * 50.
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MATHEMATICA
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Prime@Select[Range[2, 1657], Mod[Prime[ # - 1] + Prime[ # + 1], 43] == 0 &] (* Robert G. Wilson v *)
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CROSSREFS
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Cf. A000040, A112681, A112794, A112731, A112789, A112795, A112796, A112804, A112847, A112859, A113155, A113156, A113157, A113158.
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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