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 A243173 Numbers of the form x^2+15y^2. 3

%I

%S 0,1,4,9,15,16,19,24,25,31,36,40,49,51,60,61,64,69,76,79,81,85,96,100,

%T 109,115,121,124,135,136,139,141,144,151,159,160,169,171,181,184,196,

%U 199,204,211,216,225,229,235,240,241,244,249,256,265,271,276,279,285,289,304,316,321,324,331,339,340,349,360,361,375,376,379,384,391,400,409,411

%N Numbers of the form x^2+15y^2.

%C Discriminant -60.

%C Norms of numbers in Z[sqrt(-15)]. - _Alonso del Arte_, Sep 23 2014

%H Bruno Berselli, <a href="/A243173/b243173.txt">Table of n, a(n) for n = 1..1000</a>

%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 nn = 22; Union[Select[Flatten[Table[x^2 + 15 y^2, {x, 0, nn}, {y, 0, nn}]], # <= nn^2 &]] (* _Bruno Berselli_, Jun 02 2014 *)

%Y Primes: A033212.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Jun 01 2014

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Last modified September 28 18:04 EDT 2021. Contains 347716 sequences. (Running on oeis4.)