|
Search: id:A059802
|
|
|
| A059802 |
|
Numbers n such that 5^n - 4^n is prime. |
|
+0
108
|
|
| 3, 43, 59, 191, 223, 349, 563, 709, 743, 1663, 5471, 17707, 19609, 35449, 36697, 45259, 91493, 246497
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Some of the larger entries may only correspond to probable primes.
5^1663 - 4^1663, a 1163-digit number, has been certified prime with Primo. - Rick L. Shepherd (rshepherd2(AT)hotmail.com), Nov 13 2002
4 more terms found by Predrag Minovic in 2004: 35449, 36697, 45259, 91493. Corresponding numbers of decimal digits are 24778, 25651, 31635, 63951. - Alexander Adamchuk (alex(AT)kolmogorov.com), Dec 02 2006
|
|
MATHEMATICA
|
lst={}; Do[If[PrimeQ[5^n-4^n], (*Print[n]; *)AppendTo[lst, n]], {n, 10^5}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 26 2008]
|
|
CROSSREFS
|
Cf. A000043, A057468, A059801, etc.
Sequence in context: A155210 A157572 A137192 this_sequence A139854 A006033 A142184
Adjacent sequences: A059799 A059800 A059801 this_sequence A059803 A059804 A059805
|
|
KEYWORD
|
nonn,hard
|
|
AUTHOR
|
Mike Oakes (Mikeoakes2(AT)aol.com), Feb 23 2001
|
|
EXTENSIONS
|
New term 246497 found by Jean-Louis Charton in 2008 corresponding to a probable prime with 172295 digits. Jean-Louis Charton (chartonjl(AT)wanadoo.fr), Sep 02 2009
|
|
|
Search completed in 0.002 seconds
|
