A091377 Numbers having fewer prime factors than the value of their smallest prime factor.

1, 2, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 29, 31, 33, 35, 37, 39, 41, 43, 47, 49, 51, 53, 55, 57, 59, 61, 65, 67, 69, 71, 73, 77, 79, 83, 85, 87, 89, 91, 93, 95, 97, 101, 103, 107, 109, 111, 113, 115, 119, 121, 123, 125, 127, 129, 131, 133, 137, 139, 141, 143

Offset: 1

Author

Reinhard Zumkeller, Jan 04 2004

Keywords

• nonn
• easy

Comments

A091371(a(n)) > 0: A001222(a(n)) < A020639(a(n)).

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A091374, A091376, A091375.

Programs

Mathematica

Select[Range[143],PrimeOmega[#]James C. McMahon, Dec 28 2024 *)

PARI

is(n)=if(n%2==0, return(n==2)); if(n<27, return(1)); forprime(p=2,bigomega(n), if(n%p==0, return(0))); 1 \\ Charles R Greathouse IV, Sep 14 2015