cp's OEIS Frontend

A117092 Numbers n such that nextprime(2*n) > 2*nextprime(n) (here nextprime = A007918; if p is prime then nextprime(p) = p).

%I A117092 #13 Mar 31 2016 17:43:11
%S A117092 2,3,4,5,7,10,11,12,13,16,17,19,22,23,27,28,29,31,37,40,41,42,43,45,
%T A117092 46,47,52,53,57,58,59,60,61,66,67,70,71,72,73,79,82,83,87,88,89,97,
%U A117092 100,101,102,103,106,107,108,109,112,113,126,127,129,130,131,136
%N A117092 Numbers n such that nextprime(2*n) > 2*nextprime(n) (here nextprime = A007918; if p is prime then nextprime(p) = p).
%C A117092 Contains all primes (A000040), and the intersection of A006093 and A047845. - _Robert Israel_, Mar 30 2016
%H A117092 Ivan Neretin, <a href="/A117092/b117092.txt">Table of n, a(n) for n = 1..10000</a>
%e A117092 nextprime(2*12)=29 and nextprime(2)*nextprime(12)=2*13 then 12 is member because 29>26.
%p A117092 select(t -> nextprime(2*t) > 2*nextprime(t-1),[$1..100]); # _Robert Israel_, Mar 30 2016
%t A117092 Select[Range@100, NextPrime[2 #] > 2 NextPrime[# - 1] &] (* _Ivan Neretin_, Mar 30 2016 *)
%o A117092 (PARI) for(i=1,100,if(nextprime(2*i)<nextprime(2)*nextprime(i),print1(i,",")))
%Y A117092 Cf. A000040, A006093, A007918, A047845.
%K A117092 easy,nonn
%O A117092 1,1
%A A117092 Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006
%E A117092 Corrected by _T. D. Noe_, Oct 25 2006