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 A215946 #9 Aug 28 2012 18:56:09
%S A215946 0,3,31,29,0,23,19,17,13,7,0,179,0,173,1249,163,157,0,149,0,1223,137,
%T A215946 1213,127,46559,0,113,109,107,103,89,0,79,78364163957,67,0,59,53,1129,
%U A215946 43,37,0,0,23,19,17,0,60465953,1069,7547,1063,7537,0,0,1039,1033
%N A215946 Smallest prime q such that q + prime(n) is power of 6 or 0 if no such q exists.
%C A215946 Such q certainly do not exist if p == 1 (mod 10).
%C A215946 Corresponding exponents of 6 (0 if a(n)=0): 0, 0, 2, 2, 0, 2, 2, 2, 2, 2, 0, 3, 0, 3, 4, 3, 3, 0.
%H A215946 Zak Seidov, <a href="/A215946/b215946.txt">Table of n, a(n) for n = 1..162</a>
%e A215946 n=2: 3+3=6^1, n=3: 5+31=6^2, n=4: 7+29=6^2, n=6: 13+23=6^2.
%t A215946 s={0,3}; Do[p=Prime[n]; If[Mod[p,10]<2, AppendTo[s,0]; Goto[ne]]; m=Ceiling[Log[6,p]]; While[!PrimeQ[q=6^m-p], m++]; AppendTo[s,q]; Label[ne], {n, 3, 162}]; s
%Y A215946 Cf. A191474.
%K A215946 nonn
%O A215946 1,2
%A A215946 _Zak Seidov_, Aug 28 2012