|
|
A359950
|
|
a(n) is the greatest prime factor of n^n - n!.
|
|
1
|
|
|
2, 7, 29, 601, 29, 116929, 11887, 4778489, 82207, 296987, 2767, 464089, 36922117, 71722471217, 10219277051, 9406703479, 2040247819, 122450719, 1265072927, 18353142818474353, 21514105057, 46999724987, 29693667067, 5684341885088084044195811037649, 692132186353, 12114317049616531
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
2,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(5) = greatest prime factor of 5^5 - 5! = greatest prime factor of 3125 - 120 = greatest prime factor of 3005 = 3005/5 = 601.
|
|
MATHEMATICA
|
Table[Max[First/@FactorInteger[n^n-n!]], {n, 2, 27}] (* Stefano Spezia, Jan 22 2023 *)
|
|
PROG
|
(PARI) a(n) = vecmax(factor(n^n - n!)[, 1]); \\ Michel Marcus, Jan 22 2023
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|