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 A113426 #10 Mar 10 2017 21:40:04
%S A113426 2,5,11,17,23,37,47,67,83,101,127,149,167,197,227,257,293,331,359,401,
%T A113426 443,487,523,577,631,677,727,787,839,907,967,1021,1091,1153,1223,1297,
%U A113426 1367,1447,1523,1601,1693,1759,1847,1933,2027,2113,2207,2309,2399,2503
%N A113426 Greatest prime closest to n^2.
%C A113426 A060272(n) = abs(A000290(n) - a(n));
%C A113426 A113425(n) <= a(n).
%H A113426 G. C. Greubel, <a href="/A113426/b113426.txt">Table of n, a(n) for n = 1..1000</a>
%t A113426 f[n_]:=Module[{n2=n^2,np1,np2},np1=NextPrime[n2,-1];np2=NextPrime[n2];If[(n2-np1)<(np2-n2),np1,np2]]
%t A113426 Table[f[i],{i,50}]
%K A113426 nonn
%O A113426 1,1
%A A113426 _Reinhard Zumkeller_, Oct 31 2005