A123064 Numbers represented by the quadratic form 2 x^2 + xy + 4 y^2.

0, 2, 4, 5, 7, 8, 10, 14, 16, 18, 19, 20, 25, 28, 32, 35, 36, 38, 40, 41, 45, 49, 50, 56, 59, 62, 63, 64, 70, 71, 72, 76, 80, 82, 90, 94, 95, 97, 98, 100, 101, 103, 107, 109, 112, 113, 118, 124, 125, 126, 128, 133, 134, 140, 142, 144, 152, 155, 157, 160, 162, 163, 164, 171, 175

Offset

1,2

References

J. H. Conway, The Sensual (Quadratic) Form, M.A.A., 1997, p. 82.

Links

Table of n, a(n) for n=1..65.

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

Prog

(Magma) L:=LatticeWithGram(2, [4, 1, 1, 8] ); T<q> := ThetaSeries(L, 500); T;

Crossrefs

Cf. A123063, A123065, A123067, A123068.

Primes: A106872.

Sequence in context: A231979 A072013 A326669 * A108513 A029749 A018519

Adjacent sequences: A123061 A123062 A123063 * A123065 A123066 A123067

Keyword

nonn

Author

N. J. A. Sloane, Sep 27 2006

Status

approved