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A123064 Numbers represented by the quadratic form 2 x^2 + xy + 4 y^2. 7

%I

%S 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,

%T 62,63,64,70,71,72,76,80,82,90,94,95,97,98,100,101,103,107,109,112,

%U 113,118,124,125,126,128,133,134,140,142,144,152,155,157,160,162,163,164,171,175

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

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

%H N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

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

%Y Cf. A123063, A123065, A123067, A123068.

%Y Primes: A106872.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Sep 27 2006

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Last modified September 19 03:31 EDT 2021. Contains 347550 sequences. (Running on oeis4.)