OFFSET
0,1
COMMENTS
LINKS
FORMULA
EXAMPLE
Consider the first eight permutations (indices 0-7) listed in A055089:
1 [Only the first 1-cycle explicitly listed thus a(0) = 2^1 = 2]
2,1 [One transposition (2-cycle) in beginning, thus a(1) = 2^2 = 4]
1,3,2 [One fixed element in beginning, then transposition, thus a(2) = 2^1 * 3^2 = 18]
3,1,2 [One 3-cycle, thus a(3) = 2^3 = 8]
2,3,1 [One 3-cycle, thus a(4) = 2^3 = 8]
3,2,1 [One transposition jumping over a fixed element, a(5) = 2^2 * 3^1 = 12]
1,2,4,3 [Two 1-cycles, then a 2-cycle, thus a(6) = 2^1 * 3^1 * 5^2 = 150].
2,1,4,3 [Two 2-cycles, not crossed, thus a(7) = 2^2 * 5^2 = 100].
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 17 2017
STATUS
approved