A244291 Positive numbers primitively represented by the binary quadratic form (1, 6, -3).

1, 4, 13, 24, 33, 37, 52, 61, 69, 73, 88, 97, 109, 121, 132, 141, 148, 157, 169, 177, 181, 184, 193, 213, 229, 241, 244, 249, 253, 276, 277, 292, 312, 313, 321, 337, 349, 373, 376, 388, 393, 397, 409, 421, 429, 433, 436, 457, 472, 481, 484, 501, 517, 529, 537

Offset

1,2

Comments

Discriminant = 48.

Links

Table of n, a(n) for n=1..55.

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

Mathematica

Reap[For[n = 1, n < 1000, n++, r = Reduce[x^2 + 6 x y - 3 y^2 == n, {x, y}, Integers]; If[r =!= False, If[AnyTrue[{x, y} /. {ToRules[r /. C[1] -> 0]}, CoprimeQ @@ # &], Sow[n]]]]][[2, 1]] (* Jean-François Alcover, Oct 31 2016 *)

Crossrefs

Cf. A085018, A244169. A subsequence of A243168.

Sequence in context: A031240 A031320 A112263 * A085018 A255840 A001741

Adjacent sequences: A244288 A244289 A244290 * A244292 A244293 A244294

Keyword

nonn

Author

Peter Luschny, Jun 25 2014

Status

approved