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%I #11 Jan 18 2024 18:28:58
%S 13,19489357,2357967373,23225154419887808146560828362864653
%N Primes of the form 11^n+3^n-1.
%C The next term (a(5)) has 133 digits. - _Harvey P. Dale_, Jan 18 2024
%F a(n) = 11^A177030(n)+3^A177030(n)-1.
%t Select[Table[11^n+3^n-1,{n,40}],PrimeQ] (* _Harvey P. Dale_, Jan 18 2024 *)
%o (Magma) [ a: n in [0..350] | IsPrime(a) where a is 11^n+3^n-1^n]
%Y Cf. A155623, A177030
%K nonn,less
%O 1,1
%A _Vincenzo Librandi_, Dec 09 2010