

A111906


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


2



5, 7, 11, 13, 17, 19, 22, 23, 25, 26, 29, 31, 33, 34, 37, 38, 39, 41, 43, 44, 46, 47, 49, 51, 52, 53, 55, 57, 58, 59, 61, 62, 65, 67, 68, 69, 71, 73, 74, 76, 77, 79, 82, 83, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 97, 99, 101, 102, 103, 104, 106, 107, 109, 111, 113, 114, 115
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..67.


EXAMPLE

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.


PROG

(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(pc2*c)); for(n=1, m, if(v[n]>0, print1(n, ", ")))} (Klaus Brockhaus)


CROSSREFS

Cf. A111905, A111907.
Sequence in context: A035035 A256387 A113909 * A101550 A246351 A272260
Adjacent sequences: A111903 A111904 A111905 * A111907 A111908 A111909


KEYWORD

nonn


AUTHOR

Leroy Quet, Aug 19 2005


EXTENSIONS

More terms from Klaus Brockhaus, Aug 21 2005


STATUS

approved



