|
|
A045977
|
|
Smallest number with same number of divisors as n!.
|
|
1
|
|
|
1, 1, 2, 6, 24, 120, 720, 5040, 27720, 166320, 1940400, 25225200, 230630400, 3920716800, 16295479200, 97772875200, 321253732800, 9316358251200, 767582252236800, 20724720810393600, 303962571885772800, 2861985254768640000, 1212989844306240000, 44880624239330880000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
REFERENCES
|
Don McDonald to sci.math, Mar 20 1999.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
8!=40320 has 96 divisors, but 27720 is smaller with also 96 divisors. 9!=362880 has 160 divisors, but 166320 is smaller.
|
|
PROG
|
(PARI) a(n) = {nd = numdiv(n!); k = 1; while(numdiv(k) != nd, k++); k; } \\ Michel Marcus, Aug 28 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,nice,changed
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|