cp's OEIS Frontend

A192822 4-Ramanujan primes; the interval (x/2,x] has at least n 3-Ramanujan primes for x >= a(n) but not for x = a(n)-1.

%I A192822 #17 Aug 22 2012 00:20:27
%S A192822 569,571,587,1367,1373,1423,1439,2207,2237,2239,2267,2269,2273,3251,
%T A192822 3257,3259,3299,3343,3347,3449,3581,3583,3607,5639,5641,5647,5651,
%U A192822 5653,5689,5693,5737,5779,5783,5821,8059,8069,8209,8527,8537,8597,8599,8731,8747
%N A192822 4-Ramanujan primes; the interval (x/2,x] has at least n 3-Ramanujan primes for x >= a(n) but not for x = a(n)-1.
%C A192822 It is conjectured that primepi(a(n)) < 22*n for large n. - T. D. Noe, Aug 26 2011
%C A192822 The sequence is only conjectural without a proof of an upper bound on a(n) (like the bound A104272(n) < prime(3*n) proved by Laishram and used in computing Ramanujan primes). - _Jonathan Sondow_, Aug 27 2011
%C A192822 Subsequence of the 3-Ramanujan primes A192821, by the minimality of a(n). - _Jonathan Sondow_, Aug 21 2012
%Y A192822 Cf. A104272 (Ramanujan primes), A192820, A192821 (3-Ramanujan primes), A192823, A192824.
%K A192822 nonn
%O A192822 1,1
%A A192822 _T. D. Noe_, Jul 11 2011
%E A192822 Definition clarified by _Jonathan Sondow_, Aug 21 2012