

A029718


Numbers of form 2x^2 + 2xy + 3y^2.


2



0, 2, 3, 7, 8, 10, 12, 15, 18, 23, 27, 28, 32, 35, 40, 42, 43, 47, 48, 50, 58, 60, 63, 67, 72, 75, 82, 83, 87, 90, 92, 98, 103, 107, 108, 112, 115, 122, 123, 127, 128, 135, 138, 140, 147, 160, 162, 163, 167, 168, 172, 175, 178, 183, 188, 192, 200, 202, 203, 207, 210
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OFFSET

1,2


COMMENTS

Numbers represented by quadratic form with Gram matrix [ 2, 1; 1, 3 ].


REFERENCES

H. Cohn, A second course in number theory, John Wiley & Sons, Inc., New YorkLondon, 1962. see page 3.


LINKS

Table of n, a(n) for n=1..61.
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)


FORMULA

List contains 0 and all positive n such that 2*A035170(n) = A028586(n) is nonzero.  Michael Somos, Oct 21 2006


CROSSREFS

Cf. A028927.
For primes see A106865.
Sequence in context: A047532 A225378 A028808 * A206821 A323003 A051468
Adjacent sequences: A029715 A029716 A029717 * A029719 A029720 A029721


KEYWORD

nonn


AUTHOR

N. J. A. Sloane


EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Mar 29 2000


STATUS

approved



