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 A247946 #10 Jan 15 2015 16:22:58
%S A247946 7,13,181,349,673,1297,34513,90799453,175021573,4657290577,
%T A247946 17304140641,1131469145856472270556751793,
%U A247946 1544310310927991136025089626209,1442398599584422734286432395814518441223501,18598135820391234761502881488353916158281807617671450769
%N A247946 Primes in the tetranacci sequence A000288.
%C A247946 a(16) is too large to display here. It has 63 digits and is the 221st term in A000288.
%t A247946 a={1,1,1,1}; For[n=4, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], Print[sum]]; a=RotateLeft[a]; a[[4]]=sum]
%t A247946 Select[LinearRecurrence[{1,1,1,1},{1,1,1,1},300],PrimeQ] (* _Harvey P. Dale_, Jan 15 2015 *)
%Y A247946 Cf. A001590, A001631, A100683, A231574, A231575, A232543, A214899, A020992, A233554, A214727, A234696, A141523, A235862, A214825, A235873, A001630, A241660, A247027, A000288, A247561.
%K A247946 nonn
%O A247946 1,1
%A A247946 _Robert Price_, Sep 27 2014