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A172998 Numbers n such that 10^4n + 10^3n - 10^n - 3 is prime. 1

%I

%S 1,2,3,4,372

%N Numbers n such that 10^4n + 10^3n - 10^n - 3 is prime.

%C Corresponds to the numbers 10987, 100999897, 1000999998997, 10000999999989997, ...

%t fQ[n_] := PrimeQ[10^(4 n) + 10^(3 n) - 10^n - 3]; k = 1; lst = {}; While[k < 3300, If[ fQ@k, AppendTo[lst, k]]; k++ ]; lst (* _Robert G. Wilson v_, Feb 15 2010 *)

%o (PARI) is(n)=ispseudoprime(10^4*n+10^3*n-10^n-3) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn

%O 1,2

%A _James G. Merickel_, Feb 07 2010

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Last modified September 26 05:00 EDT 2020. Contains 337346 sequences. (Running on oeis4.)