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A164371 The smaller members of twin prime pairs which are non-Ramanujan primes. 6
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The terms greater than 5 of the sequence are in A164288.
LINKS
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
FORMULA
A001359 \ A104272. - R. J. Mathar, Sep 17 2009
MATHEMATICA
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 *)
PROG
(Perl) use ntheory ":all"; for (@{twin_primes(1e4)}) { say if !is_ramanujan_prime($_) } # Dana Jacobsen, Dec 30 2015
CROSSREFS
Sequence in context: A180541 A103993 A088269 * A225672 A355803 A240125
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Aug 14 2009, Aug 17 2009
EXTENSIONS
Extended by R. J. Mathar, Sep 17 2009
STATUS
approved

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Last modified March 19 07:41 EDT 2024. Contains 370958 sequences. (Running on oeis4.)