|
| |
|
|
A189100
|
|
a(n) = lcm(n!,n!')/gcd(n!,n!'), where n!' is the arithmetic derivative of n! (A068311).
|
|
5
|
|
|
|
0, 2, 30, 66, 1830, 645, 33180, 198870, 228270, 64785, 7960260, 9738960, 1663226565, 7232635410, 857066210, 1057466410, 307311194190, 767464487790, 278292627277665, 306517823106495, 35302033071305, 147385363695570, 78207294248313230, 198777858520921680
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Least common multiple of n! and its arithmetic derivative divided by greatest common divisor of n! and its arithmetic derivative.
|
|
|
LINKS
|
|
|
|
FORMULA
|
|
|
|
EXAMPLE
|
n = 5: 5! = 120, 120' = 244, gcd(120,244) = 4, lcm(120,244) = 7320, 7320/4 = 1830 -> a(5) = 1830.
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
