A091373 Number of numbers <= n having exactly as many prime factors as the value of their smallest prime factor.

0, 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 16, 16, 16, 16, 16, 16, 16, 17, 17

Offset: 1

Author

Reinhard Zumkeller, Jan 04 2004

Keywords

• nonn

Comments

a(n) = #{m: A001222(m)=A020639(m), m<=n};

A091372(n) + a(n) + A091374(n) = n.

Crossrefs

Cf. A091376, A091371.