This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A117100 #12 Jul 25 2025 21:08:10 %S A117100 16,18,28,30,38,39,40,58,72,78,81,82,88,95,96,98,99,100,106,108,130, %T A117100 138,148,150,156,170,171,172,175,176,177,178,196,198,221,222,226,228, %U A117100 231,232,237,238,240,266,267,268,280,282,310,316,348,351,352,357,358,366 %N A117100 Numbers k such that nextprime(3*k) > 3*nextprime(k) and k is composite (if p is prime then nextprime(p) = p). %o A117100 (PARI) for(i=1,200,if(nextprime(3*i)>nextprime(3)*nextprime(i) && !isprime(i),print1(i,","))) %Y A117100 Set difference of A117093 and A000040. %Y A117100 Intersection of A002808 and A117093. %Y A117100 Cf. A007918 (nextprime). %K A117100 easy,nonn %O A117100 1,1 %A A117100 Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 18 2006