cp's OEIS Frontend

A219044 Numbers k such that 3^k + 26 is prime.

%I A219044 #22 Nov 12 2023 11:15:15
%S A219044 1,3,4,5,7,9,11,16,24,28,49,53,63,88,137,184,217,299,300,732,815,999,
%T A219044 1243,1320,1397,1668,2109,2681,4973,5513,12100,14284,14592,35812,
%U A219044 38559,49687,53167,66907,88765,98251,113548,137988,139432,148008
%N A219044 Numbers k such that 3^k + 26 is prime.
%C A219044 a(45) > 2*10^5. - _Robert Price_, Nov 29 2013
%e A219044 3^3 + 26 = 53 (prime), so 3 is in the sequence.
%t A219044 Do[If[PrimeQ[3^n + 26], Print[n]], {n, 10000}]
%o A219044 (PARI) is(n)=isprime(3^n+26) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y A219044 Cf. Sequences of numbers k such that 3^k + m is prime:
%Y A219044   (m = 2) A051783, (m = -2) A014224, (m = 4) A058958, (m = -4) A058959,
%Y A219044   (m = 8) A217136, (m = -8) A217135, (m = 10) A217137, (m = -10) A217347,
%Y A219044   (m = 14) A219035, (m = -14) A219038, (m = 16) A205647, (m = -16) A219039,
%Y A219044   (m = 20) A219040, (m = -20) A219041, (m = 22) A219042, (m = -22) A219043,
%Y A219044   (m = 26) A219044, (m = -26) A219045, (m = 28) A219046, (m = -28) A219047,
%Y A219044   (m = 32) A219048, (m = -32) A219049, (m = 34) A219050, (m = -34) A219051. Note that if m is a multiple of 3, 3^k + m is also a multiple of 3 (for k greater than 0), and as such isn't prime.
%K A219044 nonn,more
%O A219044 1,2
%A A219044 _Nicolas M. Perrault_, Nov 10 2012
%E A219044 a(31)-a(44) from _Robert Price_, Nov 29 2013