31111...11111 (89-digits)

This number is a prime.

                                                        311111111 1111111111
1111111111 1111111111 1111111111 1111111111 1111111111 1111111111 1111111111

+ Term 89 in the almost repunit sequence 3, 31, 311, 3111, 31111, etc., constitutes the largest prime output within the initial one hundred terms. [Schiffman]

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