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Integers k such that 10^k + 33 is prime.
1

%I #35 Apr 20 2024 02:01:35

%S 1,3,6,9,10,31,47,70,281,366,519,532,775,1566,1627,2247,2653,4381,

%T 4571,7513,10581,13239,15393,72267,105515,215802

%N Integers k such that 10^k + 33 is prime.

%C The next term, if it exists, is > 39546. - _Robert Price_, Aug 21 2010

%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10033".

%C a(26) > 3*10^5. - _Robert Price_, Oct 26 2023

%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/prime_difficulty.txt">Search for 10w33</a>.

%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.

%e For k = 3 we get 10^3 + 33 = 1000 + 33 = 1033, which is prime, so 3 is a term.

%Y Cf. A049054, A088274, A088275, A095688, A108052, A108050, A108049, A108054.

%K nonn,more

%O 1,2

%A Julien Peter Benney (jpbenney(AT)ftml.net), Jun 08 2005

%E a(20)-a(23) from _Robert Price_, Aug 21 2010

%E Edited by _Ray Chandler_, Dec 23 2010

%E a(24) from _Robert Price_, Jan 29 2011

%E a(26) from _Robert Price_, Oct 26 2023

%E a(25) from Kamada data by _Tyler Busby_, Apr 16 2024