|
Search: id:A080830
|
|
|
| A080830 |
|
Primes that terminate at 68,34,17 in the 3x-1 problem: Repeat, if x is even divide by 2 else multiply by 3 and subtract 1, until 17 is reached. |
|
+0
1
|
|
| 17, 23, 31, 37, 41, 61, 67, 73, 83, 109, 131, 163, 179, 197, 229, 233, 239, 257, 263, 277, 293, 311, 313, 331, 337, 349, 389, 439, 443, 449, 457, 467, 491, 521, 523, 557, 577, 587, 599, 641, 659, 661, 673, 677, 701, 739, 743, 757, 761, 769, 773, 787, 829, 877
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
PROGRAM
|
(PARI) px3nm1(n, p) = { forprime(x=2, n, p1 = x; while(p1>1, if(p1%2==0, p1/=2, p1 = p1*p-1; ); if(p1 == 5 || p1==17, break); ); if(p1 == 17, print1(x" ")) ) }
|
|
CROSSREFS
|
Sequence in context: A166864 A137670 A145484 this_sequence A165566 A072184 A107644
Adjacent sequences: A080827 A080828 A080829 this_sequence A080831 A080832 A080833
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Cino Hilliard (hillcino368(AT)gmail.com), Mar 27 2003
|
|
|
Search completed in 0.002 seconds
|
