login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A140631 Primes of the form 57x^2+18xy+193y^2. 0
193, 457, 1033, 2017, 2137, 2377, 3217, 3313, 3697, 4153, 5233, 6073, 6337, 7057, 7417, 7753, 8353, 9433, 10753, 11113, 11617, 11953, 12097, 12433, 12553, 13297, 14737, 15073, 16417, 16633, 16993, 17257, 17977, 19273, 20113, 20353, 20857 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Discriminant=-43680. Also primes of the form 148x^2+132xy+177y^2.

In base 12, the sequence is 141, 321, 721, 1201, 12X1, 1461, 1X41, 1E01, 2181, 24X1, 3041, 3621, 3801, 4101, 4361, 45X1, 4X01, 5561, 6281, 6521, 6881, 6E01, 7001, 7241, 7321, 7841, 8641, 8881, 9601, 9761, 9X01, 9EX1, X4X1, E1X1, E781, E941, 100X1, where X is 10 and E is 11. Moreover, the discriminant is -21340. 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[57, 18, 193, 10000], QuadPrimes[57, -18, 193, 10000]] (* see A106856 *)

CROSSREFS

Cf. A140633.

Sequence in context: A142500 A113000 A105129 * A142117 A142564 A174521

Adjacent sequences:  A140628 A140629 A140630 * A140632 A140633 A140634

KEYWORD

nonn,easy

AUTHOR

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 13 19:58 EST 2012. Contains 205540 sequences.