|
|
A173392
|
|
Product of nonzero remainders of n mod k, for k = 1,2,3,...,n.
|
|
0
|
|
|
1, 1, 1, 1, 2, 2, 6, 12, 24, 48, 720, 240, 2160, 23040, 45360, 40320, 2419200, 1935360, 65318400, 69672960, 163296000, 2786918400, 754427520000, 22992076800, 201180672000, 14714929152000, 211843247616000, 114776447385600, 32953394073600000, 2410305395097600
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,5
|
|
LINKS
|
|
|
EXAMPLE
|
For n = 7; 7 mod k, for k = 1,2,3,...,7: (0,1,1,3,2,1,0). Product of nonzero remainders = 6. a(7) = 6.
|
|
MATHEMATICA
|
Table[Times@@DeleteCases[Mod[n, Range[n]], 0], {n, 30}]
|
|
PROG
|
(PARI) a(n) = prod(k=1, n, if (m = n % k, m, 1)); \\ Michel Marcus, May 23 2018
|
|
CROSSREFS
|
Cf. A004125 (sum of remainders of n mod k).
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|