0,2

n such that the number of primes between n and 3n (inclusive) = number of primes between n and reverse(n) (inclusive).

Table of n, a(n) for n=0..21.

14 is here since there are seven primes between 14 and 41 and seven primes between 14 and 3*14=42.

Sequence in context: A326651 A055477 A123774 * A280122 A051622 A113377

Adjacent sequences: A074812 A074813 A074814 * A074816 A074817 A074818

base,nonn

Jason Earls, Sep 08 2002

More terms from Lior Manor Sep 17 2002

approved