A111906 A number n is included if fewer primes, among primes <= the largest prime dividing n, divide n than do not.

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

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(pc-2*c)); for(n=1, m, if(v[n]>0, print1(n, ", ")))} (Klaus Brockhaus)

Crossrefs

Cf. A111905, A111907.

Sequence in context: A035035 A256387 A113909 * A348471 A101550 A320048

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