Numbers k such that 1.2. ... .k-1.k + 4 is a prime (dot between numbers means concatenation).
A099084
Numbers k such that 1.2. ... .k-1.k + 4 is a prime (dot between numbers means concatenation).
Terms
- a(0) =1a(1) =3a(2) =27a(3) =663a(4) =6919
External references
- oeis: A099084