|
Search: id:A140104
|
|
|
| A140104 |
|
A positive integer n is included if neither n-1 nor n+1 have any of the same prime-factorization exponents as n has. |
|
+0
2
|
|
| 1, 4, 8, 9, 16, 25, 26, 27, 32, 36, 64, 72, 108, 121, 125, 128, 144, 169, 196, 200, 216, 225, 243, 256, 392, 400, 432, 441, 484, 500, 512, 529, 648, 729, 784, 841, 864, 900, 961, 968, 972, 1024, 1089, 1152, 1156, 1296, 1331, 1352, 1372, 1521, 1568, 1600
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
63 has the prime-factorization 3^2 * 7^1. 64 has the prime-factorization 2^6. And 65 has the prime-factorization 5^1 * 13^1. The exponent, 6, in the prime-factorization of 64 differs from the exponents, 2 and 1, in the prime-factorization of 63 and differs from the exponents, 1 and 1, in the prime-factorization of 65. So 64 is in the sequence.
On the other hand, the prime-factorization of 39 is 3^1 * 13^1. The prime-factorization of 40 is 2^3 * 5^1. 1 occurs as both an exponent in the prime-factorization of 39 and in the prime-factorization of 40. So neither 39 nor 40 is in the sequence.
|
|
CROSSREFS
|
Sequence in context: A010390 A003624 A100657 this_sequence A127398 A109422 A158804
Adjacent sequences: A140101 A140102 A140103 this_sequence A140105 A140106 A140107
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet Jun 03 2008
|
|
EXTENSIONS
|
Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jun 26 2009
|
|
|
Search completed in 0.002 seconds
|
