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A161128 a(n) = n!*(1/1 + 1/2 + ... + 1/n) - (1! + 2! + ... + n!). 1
0, 0, 0, 2, 17, 121, 891, 7155, 63351, 617463, 6590727, 76589127, 963486567, 13052781927, 189537379047, 2937560365287, 48409889869287, 845393769958887, 15596602532173287, 303139660882458087, 6191620542649779687 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

a(n) is the number of cycles that cannot be written in the form (j,j+1,j+2,...), in all permutations of {1,2,...,n}. Example: a(3)=2 because in (1)(2)(3), (1)(23), (12)(3), (13)(2), (123), (132) we have 0+0+0+1+0+1 = 2 such cycles.

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) = A000254(n) - A007489(n).

MAPLE

a := proc (n) options operator, arrow: factorial(n)*harmonic(n)-add(factorial(j), j = 1 .. n) end proc: seq(a(n), n = 0 .. 22);

CROSSREFS

Cf. A000254, A007489.

Sequence in context: A037628 A037754 A037642 * A220403 A097716 A073510

Adjacent sequences:  A161125 A161126 A161127 * A161129 A161130 A161131

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jul 14 2009

STATUS

approved

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Last modified November 23 19:08 EST 2017. Contains 295128 sequences.