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%I #19 Aug 02 2023 06:36:48
%S 0,1,2,4,8,12,18,22,30,38,48,56,66,78,96,110,120,136,154,168,192,208,
%T 232,250,278,298,320,346,372,396,426,454,490,518,556,586,620,650,688,
%U 728,766,796,840,870,924,964,1004,1044,1098,1144,1194,1244,1296,1340,1392,1440
%N a(n) = A175341(n)/4.
%H Seiichi Manyama, <a href="/A176562/b176562.txt">Table of n, a(n) for n = 0..10000</a>
%F a(n) = A305117(n^2). - _Seiichi Manyama_, May 26 2018
%p A175341 := proc(n) local a,x,y ; a := 0 ; for x from -n to n do for y from -n to n do if x^2+y^2 <= n^2 and gcd(x,y) = 1 then a := a+1 ; end if; end do: end do: a ; end proc: seq(A175341(n)/4,n=0..40) ; # _R. J. Mathar_, Apr 20 2010
%t a89[n_] := a89[n] = Product[{p, e} = pe; Which[p < 3 && e == 1, 1, p == 2 && e > 1, 0, Mod[p, 4] == 1, 2, Mod[p, 4] == 3, 0, True, a89[p^e]], {pe, FactorInteger[n]}];
%t b[n_] := b[n] = If[n == 0, 0, b[n-1] + 4 a89[n]];
%t a[n_] := b[n^2]/4;
%t Table[a[n], {n, 0, 100}] (* _Jean-François Alcover_, Aug 02 2023 *)
%Y Cf. A175341, A305117.
%K nonn
%O 0,3
%A _Jaume Oliver Lafont_, Apr 20 2010
%E More terms from _Seiichi Manyama_, May 25 2018
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