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A152024
Largest prime factor in the subfactorial of n.
4
2, 3, 11, 53, 103, 163, 41, 16481, 1468457, 1456321, 139241, 1796801, 34361893981, 15549624751, 461702183, 65026777, 893977617157, 17562703393, 482455223267, 85836476923, 352463, 809358677, 499243508845229, 1802157757041847990541
OFFSET
3,1
LINKS
Amiram Eldar, Table of prime factors of A000166(n) for n = 3..81 (calculated with Dario Alpern's ECM)
FORMULA
a(n) = A006530(A000166(n)). - Amiram Eldar, Jul 31 2022
EXAMPLE
For n=5 (the third member of the sequence), the number of derangements is 44, thus a(5) = 11, the largest prime factor of 44.
MATHEMATICA
Table[FactorInteger[Subfactorial[n]][[-1, 1]], {n, 3, 30}] (* Amiram Eldar, Jul 31 2022 *)
PROG
(PARI) a(n) = {fn = factor(round(n!/exp(1))); fn[#fn[, 1], 1]} \\ Michel Marcus, Jun 01 2013
CROSSREFS
Sequence in context: A184315 A020133 A086528 * A353726 A353727 A041441
KEYWORD
nonn
AUTHOR
Albert Moes (albertmoes(AT)freeler.nl), Nov 20 2008
EXTENSIONS
Corrected and extended by Michel Marcus, Jun 01 2013
STATUS
approved