A023824 Sum of exponents in prime-power factorization of C(3n,n+2).

0, 2, 4, 5, 5, 6, 6, 8, 8, 8, 11, 13, 11, 11, 11, 12, 12, 13, 13, 15, 14, 17, 17, 19, 16, 16, 20, 19, 18, 18, 18, 23, 19, 18, 21, 22, 20, 22, 23, 24, 23, 24, 26, 28, 29, 27, 27, 30, 27, 28, 28, 29, 27, 31, 30, 32, 32, 31, 35, 36, 32, 31, 33, 34, 31, 32, 33, 34, 32, 34, 34, 38, 33, 35, 38, 37, 38, 36, 33

Offset

1,2

Links

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

Example

For n=4, C(12,6) = 924 = 2^2*3*7*11, so a(4) = @+1+1+1 = 5.

Mathematica

Table[Total[FactorInteger[Binomial[3n, n+2]][[All, 2]]], {n, 2, 80}] (* Harvey P. Dale, Dec 24 2016 *)

Crossrefs

Sequence in context: A061008 A256720 A091988 * A341744 A081252 A035559

Adjacent sequences: A023821 A023822 A023823 * A023825 A023826 A023827

Keyword

nonn

Author

Clark Kimberling

Extensions

a(1)=0 added by Ivan Neretin, Nov 02 2017

Status

approved