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A045897 Has both a primitive and imprimitive representation as x^2+xy+y^2. 5
49, 147, 169, 343, 361, 507, 637, 931, 961, 1029, 1083, 1183, 1369, 1519, 1813, 1849, 1911, 2107, 2197, 2401, 2527, 2793, 2883, 2989, 3211, 3283, 3549, 3577, 3721, 3871, 4107, 4459, 4489, 4557, 4693, 4753, 5047, 5239, 5329, 5341, 5439, 5547, 6223, 6241 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Index entries for sequences related to A2 = hexagonal = triangular lattice

EXAMPLE

49 = 7^2 = 5^2+5.3+3^2.

CROSSREFS

Cf. A004611, A003136.

Sequence in context: A087354 A098442 A088535 * A162942 A027469 A044381

Adjacent sequences:  A045894 A045895 A045896 * A045898 A045899 A045900

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jan 29 2009

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.