A023821 Sum of exponents in prime-power factorization of C(3n,n-2).

0, 2, 3, 3, 6, 5, 6, 8, 8, 9, 11, 9, 10, 10, 12, 11, 12, 13, 13, 14, 17, 15, 17, 17, 16, 18, 19, 17, 20, 17, 19, 21, 19, 19, 22, 20, 20, 21, 22, 21, 23, 26, 26, 28, 29, 25, 29, 28, 27, 28, 29, 26, 32, 31, 31, 32, 30, 31, 33, 33, 31, 31, 35, 33, 32, 30, 31, 32, 36, 32, 35, 34, 33, 38, 37, 35, 38, 35

Offset

2,2

Links

Ivan Neretin, Table of n, a(n) for n = 2..10000

Mathematica

Join[{0}, Table[Total[Transpose[FactorInteger[Binomial[3n, n-2]]][[2]]], {n, 3, 80}]] (* Harvey P. Dale, Sep 23 2014 *)

Crossrefs

Sequence in context: A119322 A014498 A186286 * A262332 A262240 A333660

Adjacent sequences: A023818 A023819 A023820 * A023822 A023823 A023824

Keyword

nonn

Author

Clark Kimberling

Status

approved