A243184 Nonnegative numbers of the form 2*x^2+3*x*y-3*y^2.

0, 2, 6, 8, 11, 17, 18, 24, 29, 32, 33, 41, 44, 50, 51, 54, 62, 68, 72, 74, 83, 87, 96, 98, 99, 101, 107, 116, 123, 128, 131, 132, 134, 149, 150, 153, 162, 164, 167, 173, 176, 186, 194, 197, 200, 204, 206, 216, 222, 227, 233, 239, 242, 248, 249, 261, 263, 272, 275, 281, 288, 293, 294, 296, 297

Offset

1,2

Comments

Discriminant 33.

I do not understand why the Mathematica program misses out 0.

Links

R. J. Mathar, Table of n, a(n) for n = 1..1562

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

Mathematica

Reap[For[n = 0, n <= 300, n++, If[Reduce[2*x^2 + 3*x*y - 3*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]]

Crossrefs

For primes see A141176.

Sequence in context: A136496 A183173 A178931 * A076991 A130205 A054067

Adjacent sequences: A243181 A243182 A243183 * A243185 A243186 A243187

Keyword

nonn

Author

N. J. A. Sloane, Jun 04 2014

Status

approved