|
Search: id:A075072
|
|
|
| A075072 |
|
a(1) = 1; for n > 1, a(n) = n! divided by product of factorials of all prime divisors of n. |
|
+0
1
|
|
| 1, 1, 1, 12, 1, 60, 1, 20160, 60480, 15120, 1, 39916800, 1, 8648640, 1816214400, 10461394944000, 1, 533531142144000, 1, 10137091700736000, 1689515283456000, 14079294028800, 1, 51704033477769953280000, 129260083694424883200000
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
COMMENT
|
Terms are always integers by the following classical theorem: let x(i) be k positive integers such that x(1)+x(2)+...+x(k) <= n, then x(1)!*x(2)!*...*x(k)! divides n! - Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 16 2002
|
|
EXAMPLE
|
a(12) = 12! / { 2!*3!) = 39916800.
|
|
CROSSREFS
|
Adjacent sequences: A075069 A075070 A075071 this_sequence A075073 A075074 A075075
Sequence in context: A013619 A092527 A085840 this_sequence A038327 A010204 A124607
|
|
KEYWORD
|
nice,nonn
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 09 2002
|
|
|
Search completed in 0.002 seconds
|
