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%I #17 Jan 17 2019 13:44:07
%S 2,3,9,11,12,15,36,38,41,77,90,96,132,374,399,617,1332,1395,1811,2804,
%T 4953,5310,16676,29336
%N Numbers n such that 6*10^n + 5*R_n - 2 is prime, where R_n = 11...1 is the repunit (A002275) of length n.
%C Also numbers n such that (59*10^n-23)/9 is prime.
%C a(25) > 10^5. - _Robert Price_, Sep 14 2015
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/6/65553.htm#prime">Prime numbers of the form 655...553</a>.
%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%F a(n) = A101532(n) + 1.
%t Do[ If[ PrimeQ[(59*10^n - 23)/9], Print[n]], {n, 0, 10000}]
%Y Cf. A002275, A101532.
%K more,nonn
%O 1,1
%A _Robert G. Wilson v_, Jan 18 2005
%E a(23)-a(24) from Kamada data by _Robert Price_, Dec 14 2010
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