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 A129745 #19 Aug 01 2024 09:12:54
%S A129745 5,17,19,41,43,71,1511,2339,3469,4787,7211,9781,14431
%N A129745 Numbers k such that Lucas(4k)/7 is prime.
%C A129745 L(m) = Lucas(m) = Fibonacci(m-1) + Fibonacci(m+1). 7 = L(4) divides L(4*(1+2m)) since L(4m) = L(4)*L(4*(m-1)) - L(4*(m-2)).
%C A129745 Integer k is in this sequence iff k is prime and 4k belongs to A085726. - _Max Alekseyev_, May 16 2010
%C A129745 a(14) > 60000. - _Michael S. Branicky_, Aug 01 2024
%t A129745 a=7; b=47; Do[ c=7b-a; a=b; b=c; If[ PrimeQ[c/7], Print[n] ], {n, 3, 100}]
%Y A129745 Cf. A000032, A001606 (indices of prime Lucas numbers).
%Y A129745 Cf. A074304 (numbers k such that Lucas(2k)/3 is prime).
%K A129745 less,more,nonn
%O A129745 1,1
%A A129745 _Alexander Adamchuk_, May 14 2007, May 16 2007
%E A129745 a(7) - a(10) from _Stefan Steinerberger_, May 17 2007
%E A129745 a(11) from _Max Alekseyev_, Nov 25 2007
%E A129745 a(12) from _Alexander Adamchuk_, May 15 2010
%E A129745 a(13) from _Michael S. Branicky_, Aug 01 2024