Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #3 Jun 29 2008 03:00:00
%S 16,18,28,30,38,39,40,58,72,78,81,82,88,95,96,98,99,100,106,108,130,
%T 138,148,150,156,170,171,172,175,176,177,178,196,198
%N Numbers n such that nextprime(3*n)>3*nextprime(n) and n is composite (if p is prime then nextprime(p)=p).
%o (PARI) for(i=1,200,if(nextprime(3*i)>nextprime(3)*nextprime(i) && !isprime(i),print1(i,",")))
%K easy,nonn
%O 1,1
%A Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006