12351...40041 (45-digits)

This number is a prime.

                           12351 1311277095 3815271164 8391973733 3174440041

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The smallest prime concatenated from the primeth recurrence: a(n+1) = a(n)-th prime. That is, start with 1. Concatenate the 1st prime, 2, to get 12. Concatenate the 2nd prime, 3, to get 123. Concatenate the 3rd prime, 5, to get 1235. Concatenate the 5th prime, 11, to get 123511. Continue until concatenating the 9737333th prime, 174440041. The result is, for the first time, itself a prime. [Post]