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A028927 Numbers represented by quadratic form with Gram matrix [ 3, 1; 1, 5 ]. 3
0, 3, 5, 6, 10, 12, 13, 19, 20, 21, 24, 26, 27, 35, 38, 40, 42, 45, 48, 52, 54, 59, 61, 69, 70, 75, 76, 80, 83, 84, 90, 91, 96, 101, 104, 108, 115, 117, 118, 122, 125, 131, 133, 138, 139, 140, 147, 150, 152, 157, 160, 166, 168, 171, 173, 180, 181, 182, 189, 192 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Nonnegative integers of the form 3*x^2 + 2*x*y + 5*y^2, discriminant -56. - Ray Chandler, Jul 12 2014

LINKS

Table of n, a(n) for n=1..60.

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

FORMULA

a(x_i, x_j) = 3*x_i^2 + 2*x_i*x_j + 5*x_j^2, for all x_i >= 0, x_j any integer.

CROSSREFS

Sequence in context: A072282 A257346 A047327 * A099190 A122772 A140449

Adjacent sequences:  A028924 A028925 A028926 * A028928 A028929 A028930

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Mar 28 2000

STATUS

approved

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Last modified August 20 19:51 EDT 2019. Contains 326155 sequences. (Running on oeis4.)