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%I #34 Sep 08 2022 08:46:11
%S 239,42841,20386538221561,110287289683553081554913641
%N Primes of the form 120^k - 119^k.
%C a(5) has 164 digits, a(6) has 726 digits, a(7) has 826 digits. - _Vincenzo Librandi_, Feb 22 2015
%C The values of k are 2, 3, 7, 13, 79, 349, 397, 1279, ... - _Jinyuan Wang_, May 30 2020
%H Jinyuan Wang, <a href="/A254298/b254298.txt">Table of n, a(n) for n = 1..7</a>
%H Michael P. May, <a href="https://arxiv.org/abs/1510.01028">On the Existence and Frequency Distribution of the Shell Primes</a>, arXiv preprint arXiv:1510.01028 [math.CO], 2015.
%t Select[Table[120^n - 119^n, {n, 1000}], PrimeQ] (* _Vincenzo Librandi_, Feb 22 2015 *)
%o (Magma) [a: n in [0..100] | IsPrime(a) where a is 120^n-119^n]; // _Vincenzo Librandi_, Feb 22 2015
%Y Cf. A215538.
%K nonn
%O 1,1
%A _Michael P. May_, Jan 27 2015