|
Search: id:A102308
|
|
|
| A102308 |
|
If n = product{primes p(k)|n} p(k)^b(n,p(k)), where p(k) is the kth prime that divides n (when these primes are listed from smallest to largest) and each b(n,p(k)) is a positive integer, then the sequence contains the non-prime-powers n such that p(k)^b(n,p(k)) > p(k+1) for all k, 1<=k<= -1 + number of distinct prime divisors of n. |
|
+0
2
|
|
| 12, 24, 36, 40, 45, 48, 56, 63, 72, 80, 96, 108, 112, 135, 144, 160, 175, 176, 180, 189, 192, 200, 208, 216, 224, 225, 252, 275, 288, 297, 320, 324, 325, 351, 352, 360, 384, 392, 400, 405, 416, 425, 432, 441, 448, 459, 475, 504, 513, 539, 540, 544, 567, 575
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
252 is factored as 2^2 * 3^2 * 7^1. Since 2^2 > 3 and 3^2 > 7, then 252 is in the sequence. On the other hand, 60 is factored as 2^2 * 3^1 * 5^1. Even though 2^2 > 3, 3^1 is not > 5. So 60 is not in the sequence.
|
|
CROSSREFS
|
Cf. A143907
A057715 [From Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 06 2008]
Sequence in context: A098113 A083547 A009185 this_sequence A103291 A103292 A059691
Adjacent sequences: A102305 A102306 A102307 this_sequence A102309 A102310 A102311
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet Sep 04 2008
|
|
EXTENSIONS
|
Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 06 2008
|
|
|
Search completed in 0.002 seconds
|
