data/problems/272.yml
---
:id: 272
:name: Modular Cubes, part 2
:url: https://projecteuler.net/problem=272
:content: "For a positive number <var>n</var>, define C(<var>n</var>) as the number
of the integers <var>x,</var> for which 1\\<<var>x</var>\\<<var>n</var> and \n<var>x</var><sup>3</sup>≡1
mod <var>n</var>.\n\nWhen <var>n</var>=91, there are 8 possible values for <var>x</var>,
namely : 9, 16, 22, 29, 53, 74, 79, 81. \nThus, C(91)=8.\n\nFind the sum of the
positive numbers <var>n</var>≤10<sup>11</sup> for which C(<var>n</var>)=242.\n\n"