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A006512
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Greater of twin primes.
(Formerly M3763)
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253
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5, 7, 13, 19, 31, 43, 61, 73, 103, 109, 139, 151, 181, 193, 199, 229, 241, 271, 283, 313, 349, 421, 433, 463, 523, 571, 601, 619, 643, 661, 811, 823, 829, 859, 883, 1021, 1033, 1051, 1063, 1093, 1153, 1231, 1279, 1291, 1303, 1321, 1429, 1453, 1483, 1489, 1609
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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Also primes that are the sum of two primes. - Cino Hilliard, Jul 02 2004
The set of greater of twin primes larger than five is a proper subset of the set of primes of the form 3n + 1 (A002476). - Paul Muljadi, Jun 05 2008
Smallest prime>n-th isolated composite. - Juri-Stepan Gerasimov, Nov 07 2009
Subsequence of A175075. Union of a(n) and sequence A175080 is A175075. - Jaroslav Krizek, Jan 30 2010
A164292(a(n))=1; A010051(a(n)+2)=0 for n>1. - Reinhard Zumkeller, Mar 29 2010
Omega(n)=Omega(n-2); d(n)=d(n-2). - Juri-Stepan Gerasimov, Sep 19 2010
Solutions of the equation (n-2)'+n'=2, where n' is the arithmetic derivative of n. - Paolo P. Lava, Dec 18 2012
Aside from the first term, all subsequent terms have digital root 1, 4, or 7. - J. W. Helkenberg, Jul 24 2013
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REFERENCES
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See A001359 for further references and links.
Harvey Dubner, Twin Prime Statistics, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.2.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..10000
Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.
Index entries for primes, gaps between
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MAPLE
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for i from 1 to 253 do if ithprime(i+1) = ithprime(i) + 2 then print({ithprime(i+1)}); fi; od; - Zerinvary Lajos, Mar 19 2007
P := select(isprime, [$1..1609]): select(p->member(p-2, P), P); - Peter Luschny, Mar 03 2011
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MATHEMATICA
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Select[ Prime[ Range[254]], PrimeQ[ # - 2] &] (from Robert G. Wilson v, Jun 09 2005)
Transpose[Select[Partition[Prime[Range[300]], 2, 1], Last[#]-First[#] == 2&]][[2]] (* Harvey P. Dale, Nov 02 2011 *)
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PROG
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(PARI) select(primes(1000), p->isprime(p-2)) \\ version 2.4.2 and before
select(p->isprime(p-2), primes(1000)) \\ newer versions
(MAGMA) [n: n in PrimesUpTo(1610)|IsPrime(n-2)]; // Bruno Berselli, Feb 28 2011
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CROSSREFS
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Cf. A001359, A014574, A067829, A002476.
Bisection of A077800.
Subsequence of A139690.
Sequence in context: A189441 A106986 A218011 * A074304 A072677 A117249
Adjacent sequences: A006509 A006510 A006511 * A006513 A006514 A006515
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KEYWORD
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nonn,nice,easy
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AUTHOR
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N. J. A. Sloane
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), Dec 04 2000
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STATUS
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approved
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