|
|
A164041
|
|
Primes of the form 2*p^2 + 4*p + 1, where p is also prime.
|
|
2
|
|
|
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;
text;
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
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Select[Table[2p^2+4p+1, {p, Prime[Range[200]]}], PrimeQ] (* Harvey P. Dale, Aug 25 2019 *)
|
|
PROG
|
(Magma) [a: p in PrimesUpTo(700)|IsPrime(a) where a is 2*p^2+4*p+1 ] // Vincenzo Librandi, Sep 01 2012
(PARI) lista(nn) = {forprime(p=2, nn, if(isprime(q=2*p^2+4*p+1), print1(q, ", "))); } \\ Altug Alkan, Mar 29 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|