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A164371
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The smaller members of twin prime pairs which are non-Ramanujan primes.
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6
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3, 5, 137, 191, 197, 521, 617, 1319, 1619, 1697, 1931, 1949, 2111, 2549, 2591, 2969, 3119, 3329, 3389, 3557, 3929, 4157, 4217, 4271, 4517, 5279, 5417, 7331, 7349, 7757, 8009, 8429, 8837, 9011, 9281, 9437, 9857, 9929, 10007, 10037, 10457, 10529, 10859
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OFFSET
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1,1
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COMMENTS
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The terms greater than 5 of the sequence are in A164288.
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LINKS
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Dana Jacobsen, Table of n, a(n) for n = 1..10000
J. Sondow, J. W. Nicholson, and T. D. Noe, Ramanujan Primes: Bounds, Runs, Twins, and Gaps, J. Integer Seq. 14 (2011) Article 11.6.2
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FORMULA
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A001359 \ A104272. - R. J. Mathar, Sep 17 2009
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MATHEMATICA
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nn = 1000;
A001359 = Select[Prime[Range[2 nn]], PrimeQ[# + 2] &];
R = Table[0, {nn}]; s = 0;
Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s < nn, R[[s + 1]] = k], {k, Prime[3 nn]}];
A104272 = R + 1;
Complement[A001359, A104272] (* Jean-François Alcover, Oct 28 2018, after T. D. Noe in A104272 *)
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PROG
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(Perl) use ntheory ":all"; for (@{twin_primes(1e4)}) { say if !is_ramanujan_prime($_) } # Dana Jacobsen, Dec 30 2015
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CROSSREFS
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Cf. A104272, A001359, A164288, A164554
Sequence in context: A180541 A103993 A088269 * A225672 A355803 A240125
Adjacent sequences: A164368 A164369 A164370 * A164372 A164373 A164374
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KEYWORD
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nonn
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AUTHOR
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Vladimir Shevelev, Aug 14 2009, Aug 17 2009
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EXTENSIONS
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Extended by R. J. Mathar, Sep 17 2009
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STATUS
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approved
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