Consider numbers of the form ...53197531975319753, whose digits read from the right are 3,5,7,9,1,3,5,7,9,1,3,... Sequence gives lengths of these numbers that are primes.

A090744

Consider numbers of the form ...53197531975319753, whose digits read from the right are 3,5,7,9,1,3,5,7,9,1,3,... Sequence gives lengths of these numbers that are primes.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =26a(4) =1932a(5) =13422a(6) =16971

External references