Numbers k such that 81*10^(2*k) + 9*10^k + 1 is prime.

A309744

Numbers k such that 81*10^(2*k) + 9*10^k + 1 is prime.

Terms

    a(0) =1a(1) =3a(2) =17a(3) =31a(4) =7101a(5) =14183

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