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A052361 Number of permutations in the symmetric group S_n such that the size of their conjugacy class is even. 1
0, 0, 2, 20, 104, 644, 4808, 40214, 361934, 3623084, 39889024, 478937744, 6226748384, 87175900720, 1307664018464, 20922787860974, 355687393636574, 6402373361133596, 121645097789915528, 2432901997700960264, 51090942116712179744, 1124000727209301701528 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..400

MAPLE

a:= n-> n!*(1-add((binomial(n-(n mod 2), 2*k) mod 2)/((n-2*k)!*k!*2^k),

        k=0..floor(n/2))):

seq(a(n), n=1..30);  # Alois P. Heinz, May 01 2013

MATHEMATICA

a[n_] := n!*(1-Sum[Mod[Binomial[n-Mod[n, 2], 2*k], 2]/((n-2*k)!*k!*2^k), {k, 0, Floor[n/2]}]); Table[a[n], {n, 1, 30}] (* Jean-Fran├žois Alcover, Feb 17 2014, after Alois P. Heinz *)

CROSSREFS

a(n) = n! - A088042(n).

Sequence in context: A103101 A267678 A009357 * A001884 A028477 A073077

Adjacent sequences:  A052358 A052359 A052360 * A052362 A052363 A052364

KEYWORD

nonn

AUTHOR

Yuval Dekel (dekelyuval(AT)hotmail.com), Nov 07 2003

EXTENSIONS

More terms from Ray Chandler, Nov 10 2003

STATUS

approved

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Last modified October 1 03:36 EDT 2020. Contains 337441 sequences. (Running on oeis4.)