Numbers k such that k and k^2 use only the digits 0, 2, 7 and 9.
A136926
Numbers k such that k and k^2 use only the digits 0, 2, 7 and 9.
Terms
- a(0) =0a(1) =27a(2) =270a(3) =2700a(4) =27000a(5) =270000a(6) =2700000a(7) =27000000a(8) =270000000a(9) =2700000000a(10) =27000000000a(11) =270000000000
External references
- oeis: A136926