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 A140620 Primes of the form 23x^2+4xy+68y^2. 2
 23, 263, 503, 647, 887, 1223, 1583, 1823, 1847, 2063, 2207, 2447, 2687, 2903, 3407, 3527, 3623, 3767, 4007, 4463, 4703, 4943, 4967, 5087, 5303, 5807, 5903, 5927, 6263, 6863, 7127, 7487, 7583, 7823, 8087, 8423, 8447, 9623, 9767, 10007, 10247 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Discriminant=-6240. Also primes of the form 23x^2+18xy+207y^2. In base 12, the sequence is 1E, 19E, 35E, 45E, 61E, 85E, XEE, 107E, 109E, 123E, 133E, 14EE, 167E, 181E, 1E7E, 205E, 211E, 221E, 239E, 26EE, 287E, 2X3E, 2X5E, 2E3E, 309E, 343E, 34EE, 351E, 375E, 3E7E, 415E, 43EE, 447E, 463E, 481E, 4X5E, 4X7E, 569E, 579E, 595E, 5E1E, where X is 10 and E is 11. Moreover, the discriminant is -3740. - Walter Kehowski, Jun 01 2008 LINKS Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi] N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) MATHEMATICA Union[QuadPrimes2[23, 4, 68, 10000], QuadPrimes2[23, -4, 68, 10000]] (* see A106856 *) CROSSREFS Cf. A140633. Sequence in context: A022618 A042018 A125411 * A002681 A240876 A142220 Adjacent sequences:  A140617 A140618 A140619 * A140621 A140622 A140623 KEYWORD nonn,easy AUTHOR T. D. Noe, May 19 2008 STATUS approved

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Last modified June 14 08:31 EDT 2021. Contains 345018 sequences. (Running on oeis4.)