%N Length of the longest run of Ramanujan primes that are consecutive primes < 10^n.
%H J. Sondow, <a href="http://arxiv.org/abs/0907.5232"> Ramanujan primes and Bertrand's postulate</a> Amer. Math. Monthly 116 (2009), 630-635.
%H J. Sondow, J. W. Nicholson, and T. D. Noe, <a href="http://arxiv.org/abs/1105.2249"> Ramanujan Primes: Bounds, Runs, Twins, and Gaps</a>, J. Integer Seq. 14 (2011) Article 11.6.2.
%e In the sequence of primes < 10^3, there is a run of 5 Ramanujan primes, but no longer run, so a(3) = 5.
%Y Cf. A104272 (Ramanujan primes), A189994 (length of the longest run of non-Ramanujan primes < 10^n), A174602 (smallest prime that begins a run of n Ramanujan primes).
%A _Jonathan Sondow_, May 03 2011