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 A243185 Nonnegative numbers of the form -2*x^2+3*x*y+3*y^2. 1

%I #8 Jun 07 2014 19:31:40

%S 0,1,3,4,9,12,16,22,25,27,31,34,36,37,48,49,58,64,66,67,75,81,82,88,

%T 93,97,100,102,103,108,111,121,124,136,144,147,148,157,163,166,169,

%U 174,181,187,192,196,198,199,201,202,214,223,225,229,232,243,246,256,262,264,268,279,289,291,298,300

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

%C Discriminant 33.

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

%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)

%t 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]]

%Y For primes see A141177.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Jun 04 2014

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Last modified June 9 10:32 EDT 2023. Contains 363178 sequences. (Running on oeis4.)