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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A082719 Numbers k such that (89*10^(k-1) + 1)/9 is a depression prime.

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%I A082719 #35 Nov 03 2019 19:39:48
%S A082719 7,73,97,115,205,985,1227,4795,20721,133581,411591
%N A082719 Numbers k such that (89*10^(k-1) + 1)/9 is a depression prime.
%C A082719 Prime versus probable prime status and proofs are given in the author's table.
%C A082719 No other terms below 700000. - _Serge Batalov_, Sep 22 2014
%D A082719 C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.
%H A082719 Patrick De Geest, <a href="http://www.worldofnumbers.com/deplat.htm#pdp989">PDP Reference Table - 989</a>.
%H A082719 Makoto Kamada <a href="https://stdkmd.net/nrr/9/98889.htm#prime">Prime numbers of the form 988...889</a>.
%H A082719 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%e A082719 k=7 -> (89*10^(7-1) + 1)/9 = 8*(10^7 - 1)/9 + (10^6 + 1) = 8888888 + 1000001 = 9888889.
%Y A082719 Cf. A082697-A082719, A056266.
%K A082719 nonn,base,more
%O A082719 1,1
%A A082719 _Patrick De Geest_, Apr 13 2003
%E A082719 Additional PRP term 133581 from _Serge Batalov_, May 15 2010
%E A082719 Additional PRP term 411591 from _Serge Batalov_, Sep 22 2014
%E A082719 Edited by _Ray Chandler_, Nov 05 2014
%E A082719 Definition revised by _N. J. A. Sloane_, Oct 30 2019