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A023819
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Sum of exponents in prime-power factorization of C(3n,n).
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2
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1, 2, 4, 4, 4, 6, 8, 6, 7, 8, 11, 11, 11, 11, 12, 10, 12, 11, 15, 13, 13, 18, 18, 17, 16, 17, 19, 17, 18, 19, 22, 18, 18, 20, 21, 19, 21, 22, 23, 22, 21, 23, 28, 27, 27, 28, 30, 27, 28, 26, 28, 29, 28, 31, 32, 29, 31, 31, 35, 32, 33, 35, 34, 31, 30, 31, 34, 31, 32, 35, 36, 33, 34, 35, 38, 37, 36, 36
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OFFSET
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1,2
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COMMENTS
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Equivalently, sum of exponents of primes in multinomial coefficient M(3n; n,n,n)/C(2n,n).
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LINKS
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MAPLE
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with(numtheory):(combinat):a:=proc(n) if n=0 then 0 else bigomega(binomial(3*n, n)) fi end: seq(a(n), n=1..78); # Zerinvary Lajos, Apr 11 2008
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MATHEMATICA
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Table[Total[FactorInteger[Binomial[3 n, n]][[All, 2]]], {n, 78}] (* Ivan Neretin, Nov 02 2017 *)
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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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