MathDB
D 12

Source:

May 25, 2007
modular arithmeticfloor functionabstract algebranumber theoryrelatively primegroup theoryCongruences

Problem Statement

Suppose that m>2m>2, and let PP be the product of the positive integers less than mm that are relatively prime to mm. Show that P1(modm)P \equiv -1 \pmod{m} if m=4m=4, pnp^n, or 2pn2p^{n}, where pp is an odd prime, and P1(modm)P \equiv 1 \pmod{m} otherwise.