|
|
A176787
|
|
a(n) = (0!-1!+2!-3!....(-1)^(n-1)*(n-1)!) mod n.
|
|
3
|
|
|
0, 0, 2, 0, 0, 2, 4, 4, 8, 0, 5, 8, 0, 4, 5, 12, 9, 8, 15, 0, 11, 16, 19, 20, 20, 0, 17, 4, 20, 20, 10, 28, 5, 26, 25, 8, 0, 34, 26, 20, 2, 32, 6, 16, 35, 42, 7, 44, 11, 20, 26, 0, 21, 44, 5, 4, 53, 20, 33, 20, 49, 10, 53, 60, 0, 38, 6, 60, 65, 60, 65, 44, 16, 0, 20, 72, 60, 26, 5, 60, 17
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(1) = 0! mod 1 = 1 mod 1 = 0;
a(2) = (0!-1!) mod 2 = (1 - 1) mod 2 = 0;
a(3) = (0!-1!+2!) mod 3 = (1 - 1 + 2) mod 3 = 2.
|
|
MAPLE
|
|
|
MATHEMATICA
|
Table[Mod[Sum[(-1)^k*k!, {k, 0, n - 1}], n], {n, 81}] (* Michael De Vlieger, Apr 22 2015 *)
|
|
PROG
|
(PARI) a(n) = sum(k=0, n-1, (-1)^k*k!) % n; \\ Michel Marcus, Apr 22 2015
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|