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 A215113 #14 May 17 2017 03:17:38
%S A215113 1,1,2,1,2,2,1,2,2,2,1,3,2,3,1,2,2,2,2,3,1,2,2,2,3,2,2,2,3,2,2,2,2,2,
%T A215113 2,2,3,2,3,2,3,3,2,2,2,2,2,3,1,3,3,2,2,2,2,2,3,2,3,2,2,2,2,2,2,2,1,2,
%U A215113 2,2,2,3
%N A215113 a(n) is the number of different prime divisors of A214723(n).
%C A215113 The records of a(n) are a(1)=1, a(3)=2, a(12)=3, a(132)=4,... Is the sequence unbounded?
%H A215113 G. C. Greubel, <a href="/A215113/b215113.txt">Table of n, a(n) for n = 1..5000</a>
%F A215113 a(n) = A001221(A214723(n)). - _Michel Marcus_, Feb 08 2016
%t A215113 nn = 2000; ps = Prime[Range[PrimePi[Sqrt[nn]]]]; t = Flatten[Table[ ps[[i]]^2 + ps[[j]]^2, {i, Length[ps]}, {j, i, Length[ps]}]]; t =
%t A215113 Select[t, # <= nn &]; PrimeNu[Sort[Transpose[Select[Tally[t], #[[2]] == 1 &]][[1]]]] (* _G. C. Greubel_, May 16 2017 *)
%Y A215113 Cf. A001221, A214723.
%K A215113 nonn
%O A215113 1,3
%A A215113 _Vladimir Shevelev_, Aug 03 2012