The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A106972 Primes of the form 5x^2+4xy+5y^2, with x and y any integer. 1
5, 17, 41, 89, 101, 173, 257, 269, 293, 353, 461, 509, 521, 593, 677, 761, 773, 797, 857, 881, 929, 941, 1013, 1049, 1097, 1109, 1181, 1193, 1217, 1277, 1301, 1361, 1433, 1553, 1601, 1613, 1637, 1697, 1721, 1889, 1949, 1973, 2141, 2273, 2309 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Discriminant=-84.
Primes = 5, 17, or 41 (mod 84).
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[5, 4, 5, 10000], QuadPrimes2[5, -4, 5, 10000]] (* see A106856 *)
CROSSREFS
Sequence in context: A097121 A007904 A139545 * A086499 A097123 A139562
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, May 09 2005
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 14 07:57 EDT 2024. Contains 372530 sequences. (Running on oeis4.)