|
| |
|
|
A164041
|
|
Primes of the form 2*p^2+4*p+1, where p is also prime.
|
|
1
| |
|
|
17, 31, 71, 127, 647, 1151, 2887, 3527, 7687, 12799, 19207, 20807, 23327, 34847, 39199, 49927, 53791, 73727, 79999, 103967, 117127, 145799, 172871, 194687, 220447, 279751, 294911, 323207, 336199, 387199, 394271, 419527, 438047, 587527, 649799, 724807
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| A subsequence of the primes of the form 2k^2+4k+1 = 2*(k+1)^2-1, A066436. - R. J. Mathar, Aug 10 2009
|
|
|
FORMULA
| a(n) = 2*(A164042(n))^2+4*A164042(n)+1.
|
|
|
MATHEMATICA
| lst={}; Do[p=Prime@n; a=2*p^2+4*p+1; If[PrimeQ@a, AppendTo[lst, a]], {n, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 12 2009]
|
|
|
CROSSREFS
| Sequence in context: A134076 A160961 A167496 * A085598 A163443 A027722
Adjacent sequences: A164038 A164039 A164040 * A164042 A164043 A164044
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 08 2009
|
|
|
EXTENSIONS
| a(29) corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 11 2009
Edited by N. J. A. Sloane, Aug 11 2009
|
| |
|
|
