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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A106930 Primes of the form x^2-xy+16y^2, with x and y nonnegative. 2
67, 79, 127, 163, 277, 373, 421, 463, 541, 547, 571, 613, 631, 739, 823, 877, 967, 1009, 1033, 1051, 1087, 1093, 1129, 1213, 1297, 1579, 1621, 1663, 1723, 1831, 1933, 1999, 2011, 2179, 2251, 2269, 2293, 2377, 2389, 2437, 2503, 2557, 2683, 2689, 2731, 2767 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Discriminant=-63. See A106856 for more information.

This appears to coincide with the sequence of primes of the form x^2+63y^2. - Artur Jasinski, Apr 24 2008

MATHEMATICA

QuadPrimes[1, -1, 16, 10000] (* see A106856 *)

PROG

(PARI) {a(n)= local(m, c, x); if(n<1, 0, c=0; m=1; while( c<n, m++; if( isprime(m), for(x=0, sqrtint(m\7), if(issquare(m-7*x^2), if( x%3==0, c++); break)))); m)} /* Michael Somos May 28 2005 */

CROSSREFS

Sequence in context: A044035 A124476 A066475 * A106929 A173040 A091490

Adjacent sequences:  A106927 A106928 A106929 * A106931 A106932 A106933

KEYWORD

nonn,easy

AUTHOR

T. D. Noe (noe(AT)sspectra.com), May 09 2005

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 16 21:51 EST 2012. Contains 205978 sequences.