Numbers k such that (i) k is a concatenation of consecutive natural numbers starting at 1 and (ii) k+1 is prime.
A069048
Numbers k such that (i) k is a concatenation of consecutive natural numbers starting at 1 and (ii) k+1 is prime.
Terms
- a(0) =1a(1) =12a(2) =123456
External references
- oeis: A069048