Can anyone help me understand how to find nth catalan number mod a prime number? I found this but am not able to understand it. (the last solution posted by Ben Voigt) I am lost at the line Use the Sieve of Eratosthenes to find and store pairs of factors for all composite number sieve What does it mean and how to find it? I couldn't make out this part in the code provided there P.S. I understand the approach. Just not the implementations. Thanks asked 18 Mar '15, 15:04

answered 18 Mar '15, 20:10

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