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 A124896 #13 Dec 19 2024 23:39:33
%S A124896 1,1,2,1,4,2,5,4,6,4,9,3,11,6,7,7,14,5,16,8,11,8,19,7,20,11,16,12,24,
%T A124896 8,26,15,18,15,23,11,33,16,21,15,34,10,38,19,23,20,41,15,38,19,29,22,
%U A124896 46,15,38,22,33,26,53,15,52,26,32,30,48,18,59,30,40,22,62,21,64,32,39,34
%N A124896 Number of squarefree numbers of the form n^2 + k^2, 1<=k<=n.
%C A124896 a(n) = Sum(A008966(A070216(n,k)):1<=k<=n) = Sum(ABS(A124895(n,k)):1<=k<=n).
%C A124896 0 < a(n) <= n-1.
%H A124896 Robert Israel, <a href="/A124896/b124896.txt">Table of n, a(n) for n = 1..10000</a>
%p A124896 f:= proc(n) local k; nops(select(numtheory:-issqrfree, [seq(n^2+k^2,k=1..n)])) end proc:
%p A124896 map(f, [$1..100]); # _Robert Israel_, Dec 18 2024
%t A124896 Count[#,_?SquareFreeQ]&/@Table[n^2+k^2,{n,80},{k,n}] (* _Harvey P. Dale_, Mar 30 2012 *)
%o A124896 (PARI) a(n) = sum(k=1, n, issquarefree(n^2 + k^2)); \\ _Michel Marcus_, Dec 18 2024
%Y A124896 Cf. A008966, A070216, A124895.
%K A124896 nonn,look
%O A124896 1,3
%A A124896 _Reinhard Zumkeller_, Nov 12 2006