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A220274
a(n) is the smallest number such that for all N >= a(n) there are at least n primes between 9*N and 10*N.
3
2, 14, 23, 23, 34, 36, 57, 58, 60, 60, 77, 86, 100, 100, 102, 123, 149, 149, 149, 149, 187, 187, 200, 200, 200, 202, 209, 227, 234, 268, 269, 269, 270, 319, 319, 331, 332, 332, 333, 345, 347, 350, 350, 353, 359, 360, 377, 401, 421, 440, 449, 479, 479, 487, 491
OFFSET
1,1
LINKS
N. Amersi, O. Beckwith, S. J. Miller, R. Ronan, and J. Sondow, Generalized Ramanujan primes, arXiv:1108.0475 [math.NT], 2011.
N. Amersi, O. Beckwith, S. J. Miller, R. Ronan, and J. Sondow, Generalized Ramanujan primes, Combinatorial and Additive Number Theory, Springer Proc. in Math. & Stat., CANT 2011 and 2012, Vol. 101 (2014), 1-13
Vladimir Shevelev, Ramanujan and Labos primes, their generalizations, and classifications of primes, J. Integer Seq. 15 (2012) Article 12.5.4
Vladimir Shevelev, Сharles R. Greathouse IV, and Peter J. C. Moses, On intervals (kn, (k+1)n) containing a prime for all n>1, arXiv:1212.2785 [math.NT], 2012.
FORMULA
a(n) <= ceiling(R_(10/9)(n)/10), where R_v(n) (v>1) are generalized Ramanujan numbers (see Shevelev's link). In particular, for n >= 1, {R_(10/9) (n)} = {127, 223, 227, 269, 349, 359, 569, 587, 593, 739, 809, 857, 991, 1009, ...}. Moreover, if R_(10/9)(n) == 1 (mod 10), then a(n) = ceiling(R_(10/9)(n)/10).
CROSSREFS
KEYWORD
nonn
STATUS
approved