1,1

E.g. from sequence of the valid primes (A072686) there are three prime length primes between 1 and 10: 2,3,7; therefore a(1)=3.

Cf. A072686.

Sequence in context: A065914 A108262 A034892 this_sequence A110561 A107991 A007175

Adjacent sequences: A072684 A072685 A072686 this_sequence A072688 A072689 A072690

easy,more,nonn,word

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 02 2002