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 A286579 #11 Dec 21 2021 10:15:32
%S A286579 1,2,1,2,3,4,3,4,5,6,1,2,7,8,5,6,9,10,7,8,11,12,3,1,13,14,9,10,15,16,
%T A286579 11,12,17,18,2,4,19,20,13,14,21,22,15,16,23,24,5,6,25,26,17,18,27,28,
%U A286579 19,20,29,30,3,1,31,32,21,22,33,34,23,24,35,36,7,8,37,38,25,26,39,40,27,28,41,42,9,1,43,44,29
%N A286579 Ordinal transform of A112049.
%H A286579 Antti Karttunen, <a href="/A286579/b286579.txt">Table of n, a(n) for n = 1..32768</a>
%t A286579 A112049[n_] := For[i = 1, i <= 2n, i++, If[KroneckerSymbol[i, 2n+1] < 1, Return[PrimePi[i]]]];
%t A286579 b[_] = 0;
%t A286579 a[n_] := a[n] = With[{t = A112049[n]}, b[t] = b[t]+1];
%t A286579 Array[a, 105] (* _Jean-François Alcover_, Dec 21 2021 *)
%Y A286579 Cf. A112049.
%K A286579 nonn
%O A286579 1,2
%A A286579 _Antti Karttunen_, May 26 2017