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A140625 Primes of the form 28x^2+20xy+85y^2. 0
157, 277, 397, 613, 733, 757, 853, 997, 1213, 1453, 1597, 2053, 2437, 2557, 2677, 2797, 3037, 3253, 3733, 3877, 4357, 4813, 4957, 5077, 5413, 5557, 6277, 6637, 6733, 6997, 7237, 7573, 8053, 8293, 8893, 9013, 9277, 9397, 9733, 9973, 10093 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Discriminant=-9120. Also primes of the form 45x^2+30xy+157y^2.

In base 12, the sequence is 111, 1E1, 291, 431, 511, 531, 5E1, 6E1, 851, X11, E11, 1231, 14E1, 1591, 1671, 1751, 1911, 1X71, 21E1, 22E1, 2631, 2951, 2X51, 2E31, 3171, 3271, 3771, 3X11, 3X91, 4071, 4231, 4471, 47E1, 4971, 5191, 5271, 5451, 5531, 5771, 5931, 5X11, where X is 10 and E is 11. Moreover, the discriminant is -5340. Keep in mind that 12 is a canonical base for mathematics in general since any prime greater than 3 is of the form 6k+-1, any prime of the form 4k+1 is a sum of squares while any prime of the form 4k+3 is never a sum of squares and lcm(6,4)=12. - Walter A. Kehowski (wkehowski(AT)cox.net), Jun 01 2008

MATHEMATICA

Union[QuadPrimes[28, 20, 85, 10000], QuadPrimes[28, -20, 85, 10000]] (* see A106856 *)

CROSSREFS

Cf. A140633.

Sequence in context: A142367 A001837 A142581 * A142874 A060974 A073277

Adjacent sequences:  A140622 A140623 A140624 * A140626 A140627 A140628

KEYWORD

nonn,easy

AUTHOR

T. D. Noe (noe(AT)sspectra.com), May 19 2008

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Last modified February 16 10:53 EST 2012. Contains 205904 sequences.