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 A091158 #12 Jul 31 2015 12:48:52
%S A091158 1,4,7,8,10,11,16,20,23,26,28,35,40,56,58,80,83,92,98,100,307,416,575,
%T A091158 691,746,818,820,971,1391,1487,2000,2200,2368,2386,3043,4076,4868,
%U A091158 6536,6776,6787,8008,11915,18898
%N A091158 Indices of terms in the sequence 3, 1, 4, 5, 9, 14, 23, ... (A000285 prefixed with 3) which are prime numbers.
%t A091158 Join[{1},Flatten[Position[LinearRecurrence[{1,1},{1,4},19000], _?PrimeQ]] +1] (* _Harvey P. Dale_, Nov 17 2013 *)
%Y A091158 Cf. A000285, A091157.
%K A091158 nonn
%O A091158 1,2
%A A091158 _G. L. Honaker, Jr._, Dec 23 2003
%E A091158 More terms from _Ray Chandler_, Jan 04 2004