This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A291853 #16 Sep 08 2022 08:46:19 %S A291853 3,4,7,11,83,149,223,599,647,1373,8423 %N A291853 Numbers n such that (3^n - (-2)^n)/5 is prime. %C A291853 a(12) > 65535. Presumably, a(12) = 149497 and a(13) = 388897. %e A291853 4 is in this sequence because (3^4 - (-2)^4)/5 = 13 is prime. %t A291853 Select[Range[2000], PrimeQ[(3^# - (-2)^#)/5] &] (* _Michael De Vlieger_, Dec 09 2017 *) %o A291853 (Magma) [n: n in [1..1000] | IsPrimePower((3^n-(-2)^n) div 5)]; %Y A291853 Supersequence A057469. %Y A291853 Cf. A107036 (numbers n such that (2^n-(-1)^n)/3 is prime). %K A291853 nonn,more %O A291853 1,1 %A A291853 _Juri-Stepan Gerasimov_, Sep 04 2017