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%I A111022 #15 Jan 17 2019 13:44:08
%S A111022 0,1,2,4,10,40,55,162,264,506,870,948,1339,3587,6428,48490,81487
%N A111022 Integers n such that 8*10^n+21 is prime.
%C A111022 See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "80021".
%C A111022 a(18) > 10^5. - _Robert Price_, Feb 06 2017
%H A111022 Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/">List of near-repdigit-related prime numbers</a>.
%H A111022 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%e A111022 n = 4 is a member because: 8*10^4+21 = 8*10000+21 = 80000+21 = 80021, which is prime.
%Y A111022 Cf. A049054, A088274, A088275, A095688, A107083, A108049, A108050, A108052, A108054, A110980.
%K A111022 more,nonn
%O A111022 1,3
%A A111022 Julien Peter Benney (jpbenney(AT)ftml.net), Oct 04 2005
%E A111022 a(15) from _Ray Chandler_, Dec 23 2010
%E A111022 Prepended a(1)=0 and a(2)=1 by _Robert Price_, Feb 06 2017
%E A111022 a(16)-a(17) from _Robert Price_, Feb 06 2017

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