

A295820


Number of nonnegative solutions to (x,y) = 1 and x^2 + y^2 <= n.


4



0, 2, 3, 3, 3, 5, 5, 5, 5, 5, 7, 7, 7, 9, 9, 9, 9, 11, 11, 11, 11, 11, 11, 11, 11, 13, 15, 15, 15, 17, 17, 17, 17, 17, 19, 19, 19, 21, 21, 21, 21, 23, 23, 23, 23, 23, 23, 23, 23, 23, 25, 25, 25, 27, 27, 27, 27, 27, 29, 29, 29, 31, 31, 31, 31, 35, 35, 35, 35, 35, 35
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OFFSET

0,2


LINKS



FORMULA

a(n) = a(n1) + A295819(n) for n > 0.


EXAMPLE

Solutions to (x,y) = 1 and x^2 + y^2 <= 17;
* (1,4)
* * (1,3), (2,3)
* * (1,2), (3,2)
* * * * * (0,1), (1,1), (2,1), (3,1), (4,1)
* (1,0)
a(17) = 11.


MATHEMATICA

a[n_] := Sum[Boole[GCD[i, j]==1 ], {i, 0, Sqrt[n]}, {j, 0, Sqrt[ni^2]}];


PROG

(PARI) a(n) = {sum(i=0, sqrtint(n), sum(j=0, sqrtint(ni^2), gcd(i, j) == 1))} \\ Andrew Howroyd, Dec 12 2017


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



