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A195209 Sum of even divisors of !n. 0
0, 0, 0, 2, 0, 72, 0, 2704, 0, 268128, 0, 17621496, 0, 4974281208, 0, 549790303712, 0, 245357774621280, 0, 67684833350266496, 0, 36434223374991414336, 0, 10781900341537812480000, 0, 14585451990785851336761600 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..25.

EXAMPLE

a(7) = 2704 because the divisors of  !7 = 1854 are  {1, 2, 3, 6, 9, 18, 103, 206, 309, 618, 927, 1854}, and the sum of the 6  even divisors  2, 6, 18, 206, 618 and 1854 is 2704.

MATHEMATICA

Table[Total[Select[Divisors[Subfactorial[n]], EvenQ[ # ]&]], {n, 0, 25}]

CROSSREFS

Cf. A000166, A195207.

Sequence in context: A012694 A264437 A306061 * A098276 A215880 A030129

Adjacent sequences:  A195206 A195207 A195208 * A195210 A195211 A195212

KEYWORD

nonn

AUTHOR

Michel Lagneau, Sep 13 2011

STATUS

approved

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Last modified December 11 23:44 EST 2019. Contains 329945 sequences. (Running on oeis4.)