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 A219674 #11 Nov 29 2012 12:31:49
%S A219674 1,3,5,7,13,19,17,11,23,31,67,41,29,43,47,37,71,53,61,59,73,101,79,89,
%T A219674 97,83,109,113,107,151,127,103,131,149,137,139,163,173,157,179,167,
%U A219674 181,193,191,197,229,199,223,239,227,241,233,211,251,257,271,269,313,263
%N A219674 a(n) = smallest prime not included earlier such that a(n-4) + a(n-3) + a(n-2) + a(n-1) + a(n) is a prime, with a(1)=1, a(2)=3, a(3)=5, and a(4)=7.
%t A219674 f[s_List] := Block[{pn = s[[-4]] + s[[-3]] + s[[-2]] + s[[-1]], p = 2}, While[ MemberQ[s, p] || ! PrimeQ[p + pn], p = NextPrime@ p]; Append[s, p]]; Nest[f, {1, 3, 5, 7}, 55]
%Y A219674 Cf. A073653.
%K A219674 easy,nonn
%O A219674 1,2
%A A219674 _Robert G. Wilson v_, Nov 28 2012