OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
FORMULA
a(n) = A305117(n^2). - Seiichi Manyama, May 26 2018
MAPLE
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
MATHEMATICA
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]}];
b[n_] := b[n] = If[n == 0, 0, b[n-1] + 4 a89[n]];
a[n_] := b[n^2]/4;
Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Aug 02 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaume Oliver Lafont, Apr 20 2010
EXTENSIONS
More terms from Seiichi Manyama, May 25 2018
STATUS
approved