Numbers k such that k and k^2 use only the digits 4, 5, 6 and 7.
A137139
Numbers k such that k and k^2 use only the digits 4, 5, 6 and 7.
Terms
- a(0) =74a(1) =76a(2) =74476a(3) =74474476
External references
- oeis: A137139
A137139
Numbers k such that k and k^2 use only the digits 4, 5, 6 and 7.