OFFSET
1,3
COMMENTS
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..200
D. M. Jackson, Some Combinatorial Problems Associated with Products of Conjugacy Classes of the Symmetric Group, Journal of Combinatorial Theory, Series A, 49 363-369(1988).
FORMULA
a(n) = (1/24) * (n^2 - 1) * n^(n + 1).
EXAMPLE
a(2) = 1 because in S_2 the only way to write (12) as a product of 3 transpositions is (12) = (12)(12)(12).
MAPLE
for n from 1 to 30 do printf(`%d, `, 1/24 * (n^2 - 1) * n^(n + 1)) od:
PROG
(PARI) a(n)={(n^2 - 1) * n^(n + 1)/24} \\ Harry J. Smith, Jul 07 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Dan Fux (dan.fux(AT)OpenGaia.com or danfux(AT)OpenGaia.com), Apr 13 2001
EXTENSIONS
More terms from James A. Sellers, Apr 13 2001
STATUS
approved