A085616 Numbers n == 3 (mod 8) such that there is only one solution to i^2+j^2+k^2=n, i >= j >= k >= 0.

3, 11, 19, 35, 43, 67, 91, 115, 163, 235, 403, 427

Offset

1,1

Links

Table of n, a(n) for n=1..12.

P. T. Bateman and E. Grosswald, Positive integers expressible as a sum of three squares in essentially only one way, J. Number Theory, 19 (1984), 301-308.

Mathematica

aQ[n_] := Mod[n, 8]==3 && Length[Solve[i^2+j^2+k^2==n && k>=0 && j>=k && i>=j, {i, j, k}, Integers]] == 1; Select[Range[500], aQ] (* Amiram Eldar, Dec 04 2018 *)

Crossrefs

Cf. A086719.

Sequence in context: A018557 A270528 A213540 * A138723 A099955 A138724

Adjacent sequences: A085613 A085614 A085615 * A085617 A085618 A085619

Keyword

nonn,fini,full

Author

N. J. A. Sloane, Jul 31 2003

Status

approved