|
Search: id:A009490
|
|
|
| A009490 |
|
Number of distinct orders of permutations of n objects; number of nonisomorphic cyclic subgroups of symmetric group S_n. |
|
+0
9
|
|
| 1, 1, 2, 3, 4, 6, 6, 9, 11, 14, 16, 20, 23, 27, 31, 35, 43, 47, 55, 61, 70, 78, 88, 98, 111, 123, 136, 152, 168, 187, 204, 225, 248, 271, 296, 325, 356, 387, 418, 455, 495, 537, 581, 629, 678, 732, 787, 851, 918, 986, 1056, 1133, 1217, 1307, 1399, 1498, 1600, 1708, 1823
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
Also number of different lcm's of partitions of n.
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n=0..1000
Index entries for sequences related to lcm's
|
|
FORMULA
|
Sum(b(k), k=0..n), where b(k) is the number of partitions of k into distinct prime power parts (1 excluded) (A051613) - Vladeta Jovovic (vladeta(AT)eunet.rs)
G.f.: Prod(p prime, 1 + Sum(k >= 1, x^(p^k))) / (1-x) - David W. Wilson (davidwwilson(AT)comcast.net), Apr 19, 2000
|
|
MATHEMATICA
|
Table[ Length[ Union[ Apply[ LCM, Partitions[ n ], 1 ] ] ], {n, 30} ]
|
|
CROSSREFS
|
Cf. A051613, A000792, A000793, A034891.
Sequence in context: A073061 A006874 A034890 this_sequence A064778 A028335 A007464
Adjacent sequences: A009487 A009488 A009489 this_sequence A009491 A009492 A009493
|
|
KEYWORD
|
nonn,nice,easy
|
|
AUTHOR
|
David W. Wilson (davidwwilson(AT)comcast.net)
|
|
|
Search completed in 0.003 seconds
|
