|
| |
|
|
A351710
|
|
a(n) = Sum_{p|n, p prime} (n-p)!.
|
|
0
|
|
|
|
0, 1, 1, 2, 1, 30, 1, 720, 720, 40440, 1, 3991680, 1, 479006640, 482630400, 87178291200, 1, 22230464256000, 1, 6403681380096000, 6402460884019200, 2432902008216556800, 1, 1175091669949317120000, 2432902008176640000, 620448401733245666380800, 620448401733239439360000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,4
|
|
|
LINKS
|
|
|
|
FORMULA
|
|
|
|
EXAMPLE
|
a(6) = 30; a(6) = Sum_{p|6} (6-p)! = (6-2)! + (6-3)! = 4*3*2*1 + 3*2*1 = 30.
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
