Question

Qn. 14 The square numbers and with only​

Answer 1

Answer:

of 16, 25, 36, 49, 64, 81, 121, ... (Sloane's A018884). The following table gives the first few numbers which, when squared, give numbers composed of only certain digits. The only known square number composed only of the digits 7, 8, and 9 is 9.

...

Square Number.

19 10 0, 1, 4, 5, 6, 7, 9, 11, 16, 17

20 6 0, 1, 4, 5, 9, 16