A098398 Number of primes that are not less than prime(n)-Log2(Log2(prime(n))) and not greater than prime(n)+Log2(Log2(prime(n))), where Log2=A000523.

1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 2, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2

Offset: 1

Author

Reinhard Zumkeller, Sep 06 2004

Keywords

• nonn

Comments

a(n) = A000720(A098392(n)) - A000720(A098393(n)-1);

a(n) <= A098396(n) <= A098397(n) <= A097935(n);

a(n)<=2 for n<=6543; a(6544)=#{2^16+1=65537,65539,65543}=3.

Examples

			a(10) = #{p prime: A098392(10) <= p <= A098393(10)} =
= #{p prime: 27 <= p <= 31} = #{29,31} = 2.