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A129906
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n!/(n^2) when an integer.
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2
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1, 20, 630, 4480, 36288, 3326400, 444787200, 5811886080, 81729648000, 19760412672000, 6082255020441600, 115852476579840000, 2322315553259520000, 1077167364120207360000, 24817936069329577574400, 596585001666576384000000, 14936720782466875392000000
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OFFSET
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1,2
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COMMENTS
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Also see comments in A046022 = primes together with 1 and 4.
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LINKS
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FORMULA
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{n!/(n^2) when an integer} = {n!/(n^2) where n is a nonnegative integer other than 4 or a prime} = {A000142(n)/A000290(n) when an integer.
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MATHEMATICA
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f[n_]:=If[PrimeQ[n]||n == 4, 0, n!/n^2]; Select[Table[f[n], {n, 1, 40}], #>0&] (* Geoffrey Critzer, Oct 26 2012 *)
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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