A117100 Numbers k such that nextprime(3*k) > 3*nextprime(k) and k is composite (if p is prime then nextprime(p) = p).

16, 18, 28, 30, 38, 39, 40, 58, 72, 78, 81, 82, 88, 95, 96, 98, 99, 100, 106, 108, 130, 138, 148, 150, 156, 170, 171, 172, 175, 176, 177, 178, 196, 198, 221, 222, 226, 228, 231, 232, 237, 238, 240, 266, 267, 268, 280, 282, 310, 316, 348, 351, 352, 357, 358, 366

Offset: 1

Author

Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006

Keywords

• easy
• nonn

Crossrefs

Set difference of A117093 and A000040.

Intersection of A002808 and A117093.

Cf. A007918 (nextprime).

Programs

PARI

for(i=1,200,if(nextprime(3*i)>nextprime(3)*nextprime(i) && !isprime(i),print1(i,",")))