|
| |
|
|
A037144
|
|
Numbers with at most 3 prime factors (counted with multiplicity).
|
|
8
| |
|
|
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 82, 83, 85, 86
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Complement of A033987: A001222(a(n))<=3; A117358(a(n))=1. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 10 2006
Also numbers such that exist permutations of all proper divisors only with coprime adjacent elements: A178254(a(n))>0. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 24 2010]
|
|
|
LINKS
| Klaus Brockhaus, Table of n, a(n) for n=1..10000
|
|
|
PROG
| (MAGMA) [ n: n in [1..86] | n eq 1 or &+[ t[2]: t in Factorization(n) ] le 3 ]; /* Klaus Brockhaus, Mar 20 2007 */
|
|
|
CROSSREFS
| Cf. A033987, A001222, A117358, A128644.
A037143 is a subsequence. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 24 2010]
Sequence in context: A121176 A028261 A119675 * A121684 A191853 A123093
Adjacent sequences: A037141 A037142 A037143 * A037145 A037146 A037147
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 10 2006
More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Mar 20 2007
|
| |
|
|
