|
| |
|
|
A158709
|
|
Primes p such that p + ceiling(p/2) is prime.
|
|
11
| |
|
|
2, 3, 7, 11, 19, 31, 47, 59, 67, 71, 127, 131, 151, 167, 179, 211, 239, 307, 311, 347, 379, 431, 439, 467, 479, 547, 571, 587, 607, 619, 631, 647, 727, 739, 787, 811, 839, 859, 907, 911, 967, 991, 1039, 1091, 1231, 1259, 1319, 1399, 1427, 1471, 1511, 1531, 1559
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Or, 2 along with primes p such that sum_{x=1..p}1-(-1)^x*x is prime. - Juri-Stepan Gerasimov, Jul 14 2009
Apart from the first term, primes of the form 4n-1 such that 6n-1 is also prime. [Charles R Greathouse IV, Nov 09 2011]
|
|
|
MATHEMATICA
| lst={}; Do[p=Prime[n]; If[PrimeQ[Ceiling[p/2]+p], AppendTo[lst, p]], {n, 6!}]; lst
|
|
|
PROG
| (PARI) forprime(p=2, 1e4, if(isprime(p+ceil(p/2)), print1(p", "))) \\ Charles R Greathouse IV, Nov 09 2011
(PARI) print1(2); forprime(p=3, 1e4, if(p%4==3&&isprime(p\4*6+5), print1(", "p))) \\ Charles R Greathouse IV, Nov 09 2011
|
|
|
CROSSREFS
| Cf. A158708
Sequence in context: A064270 A062576 A079739 * A180422 A055502 A003173
Adjacent sequences: A158706 A158707 A158708 * A158710 A158711 A158712
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| Vladimir Orlovsly (4vladimir(AT)gmail.com), Mar 24 2009
|
|
|
EXTENSIONS
| Corrected by Charles R Greathouse IV (charles.greathouse(AT)case.edu), Mar 18 2010
|
| |
|
|
