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A020675
Numbers of form 2 x^2 + 7 y^2.
1
0, 2, 7, 8, 9, 15, 18, 25, 28, 30, 32, 36, 39, 46, 50, 57, 60, 63, 65, 71, 72, 78, 79, 81, 95, 98, 100, 105, 112, 113, 114, 120, 126, 128, 130, 135, 144, 156, 161, 162, 169, 175, 177, 183, 184, 190, 191, 193, 200, 207, 210, 225, 228, 240, 242, 247, 249, 252, 254, 260, 263
OFFSET
1,2
LINKS
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
MATHEMATICA
With[{nn=80}, Take[Union[2#[[1]]+7#[[2]]&/@Tuples[Range[0, nn/4]^2, 2]], nn]] (* Harvey P. Dale, Jul 17 2015 *)
CROSSREFS
Sequence in context: A179772 A047354 A037455 * A317303 A045980 A104339
KEYWORD
easy,nonn
STATUS
approved