A237599 Positive integers k such that x^2 - 6xy + y^2 + k = 0 has integer solutions.

4, 7, 8, 16, 23, 28, 31, 32, 36, 47, 56, 63, 64, 68, 71, 72, 79, 92, 100, 103, 112, 119, 124, 127, 128, 136, 144, 151, 164, 167, 175, 184, 188, 191, 196, 199, 200, 207, 223, 224, 239, 248, 252, 256, 263, 271, 272, 279, 284, 287, 288, 292, 311, 316, 324, 328

Offset

1,1

Comments

Nonnegative numbers of the form 8x^2 - y^2. - Jon E. Schoenfield, Jun 03 2022

Links

Table of n, a(n) for n=1..56.

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Example

4 is in the sequence because x^2 - 6xy + y^2 + 4 = 0 has integer solutions, for example (x, y) = (1, 5).

Crossrefs

Cf. A001653 (k = 4), A006452 (k = 7), A001541 (k = 8), A075870 (k = 16), A156066 (k = 23), A217975 (k = 28), A003499 (k = 32), A075841 (k = 36), A077443 (k = 56).

Cf. A031363, A084917, A237351, A237606, A237609, A237610.

For primes see A007522 and A141175.

For a list of sequences giving numbers and/or primes represented by binary quadratic forms, see the "Binary Quadratic Forms and OEIS" link.

Sequence in context: A051219 A344581 A270216 * A291750 A007285 A225430

Adjacent sequences: A237596 A237597 A237598 * A237600 A237601 A237602

Keyword

nonn

Author

Colin Barker, Feb 10 2014

Status

approved