Numbers k such that k and k^2 use only the digits 2, 5, 7 and 9.
A137117
Numbers k such that k and k^2 use only the digits 2, 5, 7 and 9.
Terms
- a(0) =5a(1) =27a(2) =77a(3) =527a(4) =7227a(5) =27797977
External references
- oeis: A137117
A137117
Numbers k such that k and k^2 use only the digits 2, 5, 7 and 9.