MathDB

8

Part of 2015 Middle European Mathematical Olympiad

Problems(1)

Number of residues whose square is -1

Source: MEMO 2015, problem T-8

8/28/2015
Let n≥2n\ge 2 be an integer. Determine the number of positive integers mm such that m≤nm\le n and m2+1m^2+1 is divisible by nn.
number theorydivisorC.R.T