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A023820 Sum of exponents in prime-power factorization of C(3n,n-1). 1
0, 2, 4, 4, 4, 7, 7, 8, 8, 8, 11, 12, 9, 12, 13, 12, 11, 13, 14, 15, 14, 17, 18, 19, 16, 18, 20, 18, 18, 21, 20, 21, 19, 20, 22, 22, 19, 22, 24, 22, 21, 24, 27, 29, 28, 28, 29, 31, 27, 28, 29, 29, 28, 34, 32, 32, 31, 30, 34, 34, 32, 34, 36, 35, 31, 32, 31, 33, 33, 36, 35, 36, 32, 36, 40, 37, 36, 38 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

MATHEMATICA

Join[{0}, Table[Total[FactorInteger[Binomial[3 n, n - 1]][[All, 2]]], {n, 2, 78}]] (* Ivan Neretin, Nov 02 2017 *)

CROSSREFS

Sequence in context: A325940 A035545 A327333 * A225355 A117726 A172307

Adjacent sequences: A023817 A023818 A023819 * A023821 A023822 A023823

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified February 5 12:47 EST 2023. Contains 360084 sequences. (Running on oeis4.)