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A140614 Primes of the form 15x^2+12xy+20y^2. 1
23, 47, 71, 191, 311, 383, 599, 647, 719, 839, 863, 911, 983, 1103, 1367, 1439, 1511, 1607, 1871, 2039, 2399, 2423, 2447, 2663, 2687, 2711, 2927, 3023, 3191, 3359, 3623, 3719, 3767, 4007, 4079, 4271, 4679, 4799, 4871, 4943, 5039, 5087, 5303 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Discriminant=-1056. Also primes of the form 23x^2+12xy+36y^2.

In base 12 the sequence is 1E, 3E, 5E, 13E, 21E, 27E, 41E, 45E, 4EE, 59E, 5EE, 63E, 69E, 77E, 95E, 9EE, X5E, E1E, 10EE, 121E, 147E, 149E, 14EE, 165E, 167E, 169E, 183E, 18EE, 1X1E, 1E3E, 211E, 219E, 221E, 239E, 243E, 257E, 285E, 293E, 299E, 2X3E, 2XEE, 2E3E, 309E, where X is 10 and E is 11. Moreover, the discriminant is -740. 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), May 31 2008

MATHEMATICA

Union[QuadPrimes[15, 12, 20, 10000], QuadPrimes[15, -12, 20, 10000]] (* see A106856 *)

CROSSREFS

Cf. A140633.

Sequence in context: A183010 A141376 A134517 * A001124 A139501 A117876

Adjacent sequences:  A140611 A140612 A140613 * A140615 A140616 A140617

KEYWORD

nonn,easy

AUTHOR

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

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Last modified February 14 22:52 EST 2012. Contains 205685 sequences.