Palindromic Squares with Non-Palindromic Roots

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Theorem

The sequence of palindromic squares with non-palindromic square roots begins:

$676, 69 \, 696, 94 \, 249, 698 \, 896, 5 \, 221 \, 225, 6 \, 948 \, 496, 522 \, 808 \, 225, \ldots$

This sequence is not explicitly given in On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).


The sequence of those corresponding non-palindromic square roots begins:

$26, 264, 307, 836, 2285, 2636, 22 \, 865, 24 \, 846, 30 \, 693, \ldots$

This sequence is A251673 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).


Proof

By investigating all square numbers which are palindromic.

\(\ds 676\) \(=\) \(\ds 26^2\)
\(\ds 69 \, 696\) \(=\) \(\ds 264^2\)
\(\ds 94 \, 249\) \(=\) \(\ds 307^2\)
\(\ds 698 \, 896\) \(=\) \(\ds 836^2\)
\(\ds 5 \, 221 \, 225\) \(=\) \(\ds 2285^2\)
\(\ds 6 \, 948 \, 496\) \(=\) \(\ds 2636^2\)
\(\ds 522 \, 808 \, 225\) \(=\) \(\ds 22 \, 865^2\)

and so on.

$\blacksquare$


Sources