Maths Olympiad Prep

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Number theory Difficulty 5.5 AIME, harder Find the answer

2. Find the first ten terms of the sequence of pseudo-random numbers generated by the linear congruential method with x0=6x_{0}=6 and xn+15xn+2(mod19)x_{n+1} \equiv 5 x_{n}+2(\bmod 19). What is the period length of this generator?

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Solution

2. 6.13,10,14,15,1,7,18,16,6,13,6.13,10,14,15,1,7,18,16,6,13, \ldots period length is 9

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Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.