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%I #34 Nov 10 2019 01:33:42
%S 3,5,87,113,171,567,1689,8903,115811
%N Numbers k such that (71*10^(k-1) - 17)/9 is a plateau prime.
%C Prime versus probable prime status and proofs are given in the author's table.
%D C. Caldwell and H. Dubner, The near repdigit primes A(n-k-1)B(1)A(k), especially 9(n-k-1)8(1)9(k), Journal of Recreational Mathematics, Volume 28, No. 1, 1996-97, pp. 1-9.
%H Patrick De Geest, <a href="http://www.worldofnumbers.com/deplat.htm#pdp787">PDP Reference Table - 787</a>.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/7/78887.htm#prime">Prime numbers of the form 788...887</a>.
%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%F a(n) = A056262(n) + 2.
%e k=5 -> (71*10^(5-1) - 17)/9 = 78887.
%Y Cf. A082697-A082720, A056262.
%K nonn,base,hard,more
%O 1,1
%A _Patrick De Geest_, Apr 13 2003
%E 115811 from _Ray Chandler_, Aug 05 2011
%E a(2)=5 corrected by _Patrick De Geest_, Apr 28 2013
%E Edited by _Ray Chandler_, Nov 05 2014
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