Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #24 Jan 25 2022 08:46:53
%S 1,3,4,5,10,11,16,35,49,69,119,223,400,775,1003,1523,2225,6793,7018,
%T 13600,76801
%N Integers k such that 10^k + 69 is a prime number.
%C Next term in sequence, if one exists is > 100000. - _Robert Price_, Apr 25 2011
%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10069".
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/">List of near-repdigit-related prime numbers</a>.
%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.
%e 5 is a term because 10^5 + 69 = 100000 + 69 = 100069, which is prime.
%Y Cf. A095688, A108052, A108050, A108312, A107083, A108049, A108054.
%K nonn,more
%O 1,2
%A Julien Peter Benney (jpbenney(AT)gmail.com), Feb 12 2008
%E Term 13600 from _Robert Price_, Mar 22 2010
%E Terms 1003, 1523, 2225, 6793, 7018 inserted by _Robert Price_, Oct 31 2010
%E Edited by _Ray Chandler_, Dec 23 2010
%E a(21)=76801 from _Robert Price_, Mar 03 2011