Square of Small Repunit is Palindromic/Mistake/First Edition

Source Work

1986: David Wells: Curious and Interesting Numbers:

The Dictionary

$1,111,111,111,111,111,111$

Mistake

The squares of repunits make a pretty pattern:

For example: ... $1111111111111^2 = 12345678900987654321$

Correction

That should read:

$1111111111^2 = 1234567900987654321$

The repunit in question is of index $13$, not $10$, and there is an extra $8$ in its square.

The first of these mistakes has been corrected in Curious and Interesting Numbers, 2nd ed. of $1997$, but not the second.

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $1,111,111,111,111,111,111$