The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #13 Nov 10 2019 01:33:50
%S 3,247,1141,10395,43881
%N Numbers k such that (82*10^(k-1) + 71)/9 is a depression prime.
%C Prime versus probable prime status and proofs are given in the author's table.
%D C. Caldwell and H. Dubner, "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#pdp919">PDP Reference Table - 919</a>.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/9/91119.htm#prime">Prime numbers of the form 911...119</a>.
%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%e k=3 -> (82*10^(3-1) + 71)/9 = 919.
%Y Cf. A082697-A082720, A056264.
%K nonn,base,more
%O 1,1
%A _Patrick De Geest_, Apr 13 2003
%E One more term from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
%E Edited by _Ray Chandler_, Nov 04 2014