MathDB

A3

Part of 1970 Putnam

Problems(1)

Longest Tail on Perfect Squares

Source: 1989 IrMO Paper 1 Problem 4

9/29/2017
Note that 122=14412^2=144 ends in two 44s and 382=144438^2=1444 end in three 44s. Determine the length of the longest string of equal nonzero digits in which the square of an integer can end.
number theory