|
| |
|
|
A086086
|
|
Primes p such that p-floor(Sqrt(p)) is prime.
|
|
4
| |
|
|
3, 5, 7, 17, 23, 37, 43, 47, 67, 79, 107, 113, 149, 151, 163, 211, 257, 331, 349, 409, 421, 439, 509, 521, 587, 593, 601, 617, 709, 727, 797, 839, 907, 911, 937, 941, 1051, 1063, 1163, 1187, 1319, 1327, 1447, 1471, 1489, 1607, 1619, 1637, 1667, 1783, 1789, 1801
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
EXAMPLE
| a(5)=23 because 19 is prime and 23 - (floor(Sqrt(23)) = 23 - (floor(4.795831523)) = 23 - 4 = 19 which is prime.
|
|
|
MATHEMATICA
| f[n_]:=n-Floor[Sqrt[n]]; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst, p]], {n, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 25 2010]
|
|
|
CROSSREFS
| Sequence in context: A122853 A137258 A053341 * A141772 A032496 A002092
Adjacent sequences: A086083 A086084 A086085 * A086087 A086088 A086089
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Chuck Seggelin (barkeep(AT)plastereddragon.com), Jul 08 2003
|
|
|
EXTENSIONS
| More terms from Vladimir Orlovsky (4vladimir(AT)gmail.com), Feb 25 2010
|
| |
|
|
