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 A233554 #5 Dec 12 2013 22:37:53
%S A233554 1,3,6,15,19,22,207,542,2374,10579,17726,43182
%N A233554 Indices of primes in the tribonacci-like sequence, A020992.
%C A233554 a(13) > 2*10^5.
%t A233554 a={0,2,1};Print[1];For[n=3,n<=1000,n++,sum=Plus@@a;If[PrimeQ[sum],Print[n]];a=RotateLeft[a]; a[[3]]=sum]
%Y A233554 Cf. A001590, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498.
%K A233554 nonn
%O A233554 1,2
%A A233554 _Robert Price_, Dec 12 2013