|
|
A275064
|
|
Number of permutations p of [n] such that p(i)-i is a multiple of nine for all i in [n].
|
|
2
|
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1536, 4608, 13824, 41472, 124416, 373248, 1119744, 3359232, 10077696, 40310784, 161243136, 644972544, 2579890176, 10319560704, 41278242816, 165112971264, 660451885056, 2641807540224
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,11
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Product_{i=0..8} floor((n+i)/9)!.
|
|
MATHEMATICA
|
Table[Product[Floor[(n + i)/9]!, {i, 0, 8}], {n, 0, 40}] (* Vaclav Kotesovec, Oct 02 2018 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|