Art of Problem Solving

2024 AIME I Problems/Problem 13: Difference between revisions

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==Solution==
==Solution==


<math>n^4+1\equiv 0\pmod{p^2}\implies n^8 \equiv 1\pmod{p^2}\implies p_{min}=17</math>
From there, we could get <math>n\equiv \pm 2, \pm 8\pmod{17}</math>
By doing binomial expansion bash, the four smallest <math>n</math> in this case are <math>110, 134, 155, 179</math>, yielding <math>\boxed{110}</math>
~Bluesoul


==See also==
==See also==

Revision as of 18:44, 2 February 2024

Problem

Let $p$ be the least prime number for which there exists a positive integer $n$ such that $n^{4}+1$ is divisible by $p^{2}$. Find the least positive integer $m$ such that $m^{4}+1$ is divisible by $p^{2}$.

Solution

$n^4+1\equiv 0\pmod{p^2}\implies n^8 \equiv 1\pmod{p^2}\implies p_{min}=17$

From there, we could get $n\equiv \pm 2, \pm 8\pmod{17}$

By doing binomial expansion bash, the four smallest $n$ in this case are $110, 134, 155, 179$, yielding $\boxed{110}$

~Bluesoul

See also

2024 AIME I (ProblemsAnswer KeyResources)
Preceded by
Problem 12
Followed by
Problem 14
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
All AIME Problems and Solutions

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