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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
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
Sequence in context: A012694 A264437 A306061 * A098276 A335692 A215880
KEYWORD
nonn
AUTHOR
Michel Lagneau, Sep 13 2011
STATUS
approved

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Last modified March 19 02:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)