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A117094 Numbers k such that nextprime(5*k) > 5*nextprime(k) (if p is prime then nextprime(p) = p).

%I A117094 #21 Jul 28 2025 03:14:46
%S A117094 2,3,5,7,11,13,17,18,19,23,28,29,31,37,40,41,43,47,53,59,60,61,67,71,
%T A117094 72,73,78,79,82,83,89,96,97,101,102,103,105,106,107,109,113,127,131,
%U A117094 137,139,149,151,155,156,157,163,166,167,173,178,179,180,181,191,192,193,197,199,211,222,223,226
%N A117094 Numbers k such that nextprime(5*k) > 5*nextprime(k) (if p is prime then nextprime(p) = p).
%C A117094 Includes all primes. - _Robert Israel_, Jul 25 2025
%H A117094 Robert Israel, <a href="/A117094/b117094.txt">Table of n, a(n) for n = 1..10000</a>
%e A117094 13 is a term since nextprime(5*13) = 67 and nextprime(5)*nextprime(13) = 5*13=65 and 67 > 65.
%p A117094 select(n -> nextprime(5*n) > 5*nextprime(n-1), [$1..1000]); # _Robert Israel_, Jul 25 2025
%t A117094 Select[Range[250], NextPrime[5*#] > 5*NextPrime[# - 1] &] (* _Paolo Xausa_, Jul 28 2025 *)
%o A117094 (PARI) for(i=1,150,if(nextprime(5*i)>nextprime(5)*nextprime(i),print1(i,",")))
%Y A117094 Union of A000040 and A117101.
%Y A117094 Cf. A007918 (nextprime).
%K A117094 easy,nonn
%O A117094 1,1
%A A117094 Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006
%E A117094 More terms from _Robert Israel_, Jul 25 2025