OFFSET
4,1
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 4..50
EXAMPLE
19 is a term because 4^5 - 5^4 = 399 = 19 * 21. - Bernard Schott, Jan 14 2019
MATHEMATICA
Table[FactorInteger[(n - 1)^n - n^(n - 1)][[-1, 1]], {n, 4, 20}] (* Vincenzo Librandi, Jan 14 2019 *)
PROG
(PARI) a(n) = vecmax(factor((n-1)^n - n^(n-1))[, 1]);
for (n=4, 30, print1(a(n), ", ")) \\ Michel Marcus, Jan 14 2019
(Magma) [Maximum(PrimeDivisors((n-1)^n - n^(n-1))): n in [4..25]]; // Vincenzo Librandi, Jan 14 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Torbjorn Alm (talm(AT)tele2.se), Mar 17 2010
EXTENSIONS
a(4) corrected, a(22)-a(24) added, and other edits by Jon E. Schoenfield, Jan 13 2019
STATUS
approved