The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 0..1000 FORMULA a(n) = a(n-1) + 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[n-i^2]}]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jul 05 2018, after Andrew Howroyd *) PROG (PARI) a(n) = {sum(i=0, sqrtint(n), sum(j=0, sqrtint(n-i^2), gcd(i, j) == 1))} \\ Andrew Howroyd, Dec 12 2017 CROSSREFS Cf. A049643, A224212, A295819, A295849. Sequence in context: A284397 A284374 A137847 * A164023 A097224 A087418 Adjacent sequences: A295817 A295818 A295819 * A295821 A295822 A295823 KEYWORD nonn AUTHOR Seiichi Manyama, Nov 28 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 4 09:52 EDT 2024. Contains 374906 sequences. (Running on oeis4.)