Is there a term for numbers like 1001, 2002, 3003 or 1010, 2020, 3030

Question

If I am speaking to somebody about 4 digit numbers in specific format where the second and the third digits are the same or where the first and the third digits are the same what would be the term for them?

Answer 1

If you consider your four digit numbers as words on the alphabet $\{0, 1, \dots, 9\}$, the words of the first category are of the form $uu^r$ (where $u^r$ denotes the reverse of $u$, that is, $u$ read from right to left, if you prefer) and are called palindromes. The words of the second category are of the form $uu$ and are called squares. Of course this terminology is only used in theoretical computer science and would be ambiguous for a number.

Answer 2

The term would be "4 digit numbers where the second and the third digits are the same or where the first and the third digits are the same"