A020675 - OEIS

%I #11 Jul 17 2015 17:35:36

%S 0,2,7,8,9,15,18,25,28,30,32,36,39,46,50,57,60,63,65,71,72,78,79,81,

%T 95,98,100,105,112,113,114,120,126,128,130,135,144,156,161,162,169,

%U 175,177,183,184,190,191,193,200,207,210,225,228,240,242,247,249,252,254,260,263

%N Numbers of form 2 x^2 + 7 y^2.

%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 With[{nn=80},Take[Union[2#[[1]]+7#[[2]]&/@Tuples[Range[0,nn/4]^2,2]],nn]] (* _Harvey P. Dale_, Jul 17 2015 *)

%K easy,nonn

%O 1,2

%A _David W. Wilson_