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One notices that $5^2=4!+1$, $11^2=5!+1$, and $71^2=7!+1$. Are there others?

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closed as off topic by Felipe Voloch, Loop Space, John Bentin, Gjergji Zaimi, Emil Jeřábek Nov 9 '11 at 18:20

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This is known as Brocard's problem and is unsolved still – Aleks Vlasev Nov 9 '11 at 9:00
@Aleks: If you post this as an answer, I will accept it. – John Bentin Nov 9 '11 at 10:39