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 A248920 #5 Oct 19 2014 16:06:18
%S A248920 5,7,13,18,19,34,35,38,43,48,188,286,450,501,759,1446,2021,2419,2997,
%T A248920 3715,5677,13566,46303,57174,108844,117145,166683,178863
%N A248920 Indices of primes in the pentanacci numbers sequence A000322.
%C A248920 a(29) > 2*10^5.
%H A248920 Tony D. Noe and Jonathan Vos Post, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL8/Noe/noe5.html">Primes in Fibonacci n-step and Lucas n-step Sequences</a>, J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4
%t A248920 a={1,1,1,1,1}; For[n=5, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], Print[n]]; a=RotateLeft[a]; a[[5]]=sum]
%Y A248920 Cf. A001590, A001631, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498, A214727, A081172, A214752, A141523, A214825, A235862, A000288, A000322.
%K A248920 nonn,more
%O A248920 1,1
%A A248920 _Robert Price_, Oct 16 2014