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A023830
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Sum of exponents in prime-power factorization of C(4n,n-4).
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1
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0, 3, 4, 6, 6, 10, 8, 8, 8, 11, 12, 12, 13, 14, 15, 16, 12, 16, 15, 17, 18, 21, 17, 20, 19, 19, 22, 19, 21, 25, 25, 26, 23, 25, 25, 26, 26, 28, 25, 27, 25, 29, 28, 27, 31, 32, 31, 33, 30, 30, 31, 31, 31, 34, 32, 33, 32, 35, 35, 37, 39, 42, 42, 41, 37, 40, 41, 38, 42, 44, 40, 46, 42, 45, 46, 45, 44
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OFFSET
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4,2
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LINKS
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FORMULA
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a(n) = Omega( C(4n,n-4) ) = A001222( C(4n,n-4) ), n > 3.
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MAPLE
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MATHEMATICA
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Join[{0}, Table[Total[Transpose[FactorInteger[Binomial[4n, n-4]]][[2]]], {n, 5, 80}]] (* Harvey P. Dale, Oct 12 2014 *)
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PROG
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(PARI) a(n) = bigomega(binomial(4*n, n-4)); \\ Michel Marcus, Oct 12 2014
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CROSSREFS
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KEYWORD
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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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