A repeating number is a number such that the first half of the digits are the same as the second half of the digits. For example, 2020 is a repeating number. What is the smallest repeating number that is also a square?
(In reply to
Solution by Larry)
Nice work, I had a similar thought but you beat me to it. So I took your number 8264462810082644628100 and went over to the OEIS. That gave me A092118: Biperiod squares: square numbers whose digits repeat twice in order. Your number is the 7th smallest value according to the OEIS.
Also of note A102567: Numbers n such that n concatenated with itself is a biperiod square. (Just the repeating half of the square number) and A106497: Numbers whose square is the concatenation of two identical numbers, i.e., of the form NN. (These are the square roots of the repeating squares)
re: Solution
