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A217672
Largest k such that k^n divides k!!
0
1, 8, 16, 36, 24, 32, 60, 72, 80, 48, 135, 200, 168, 120, 297, 189, 144, 96, 160, 252, 180, 270, 539, 400, 405, 315, 336, 240, 594, 378, 192, 660, 525, 420, 288, 448, 600, 770, 320, 648, 504, 1001, 675, 360, 560, 1496, 1125, 972, 800, 810, 630, 1056, 1300, 384
OFFSET
1,2
COMMENTS
Largest k such that A217467(k)=n.
EXAMPLE
a(5)=24 because 24^5 divides 24!! but 24^6 does not divide 24!!.
MATHEMATICA
kdn[n_]:=Module[{k=2}, While[!Divisible[k!!, k^n]||Divisible[k!!, k^(n+1)], k++]; k]; Join[{1}, Array[kdn, 60, 2]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Oct 10 2012
STATUS
approved