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Search: id:A118072
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| A118072 |
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Primes which are sum of twin prime pair - 1. |
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+0
1
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| 7, 11, 23, 59, 83, 359, 383, 479, 563, 839, 863, 1283, 1319, 1619, 2039, 2063, 2099, 2459, 2579, 2903
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Subset of A072669 - Paolo P. Lava (ppl(AT)spl.at), Dec 21 2007
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FORMULA
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{A001359(k) + A006512(k) - 1} INTERSECT {A000040}. {A054735(k) - 1} INTERSECT {A000040}. {2*A001359(k) + 1} INTERSECT {A000040}.
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EXAMPLE
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a(1) = 7 = 3 + 5 - 1 where (3,5) is a twin prime pair.
a(2) = 11 = 5 + 7 - 1 where (5,7) is a twin prime pair.
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MAPLE
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P:=proc(n) local a, i; for i from 1 by 1 to n do if ithprime(i+1)-ithprime(i)=2 then a:=ithprime(i+1)+ithprime(i)-1; if isprime(a) then print(a); fi; fi; od; end: P(300); - Paolo P. Lava (ppl(AT)spl.at), Dec 21 2007
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MATHEMATICA
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lst={}; d=2; Do[p1=Prime[n]; p2=Prime[n+1]; p=p1+p2-1; If[PrimeQ[p]&&p2-p1==d, AppendTo[lst, p]], {n, 10^3}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 14 2008]
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CROSSREFS
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Cf. A000040, A001359, A005384, A006512, A054735.
Sequence in context: A163848 A111671 A140111 this_sequence A076855 A160054 A027830
Adjacent sequences: A118069 A118070 A118071 this_sequence A118073 A118074 A118075
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), May 11 2006
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