This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A111906 A number n is included if fewer primes, among primes <= the largest prime dividing n, divide n than do not. 2

%I

%S 5,7,11,13,17,19,22,23,25,26,29,31,33,34,37,38,39,41,43,44,46,47,49,

%T 51,52,53,55,57,58,59,61,62,65,67,68,69,71,73,74,76,77,79,82,83,85,86,

%U 87,88,89,91,92,93,94,95,97,99,101,102,103,104,106,107,109,111,113,114,115

%N A number n is included if fewer primes, among primes <= the largest prime dividing n, divide n than do not.

%e 22 is included because 11 is the largest prime dividing 22. And of the primes <= 11 (2,3,5,7,11), 2 and 11 (2 primes) divide 22, but 3 and 5 and 7 (3 primes) do not divide 22.

%o (PARI) {m=115;v=vector(m);for(n=1,m,f=factor(n)[,1]~;c=0;pc=0;forprime(p=2,vecmax(f), j=1;s=length(f);while(j<=s&&p!=f[j],j++);if(j<=s,c++);pc++);v[n]=sign(pc-2*c)); for(n=1,m,if(v[n]>0,print1(n,",")))} (Klaus Brockhaus)

%Y Cf. A111905, A111907.

%K nonn

%O 1,1

%A Leroy Quet Aug 19 2005

%E More terms from _Klaus Brockhaus_, Aug 21 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .