OFFSET
0,4
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
FORMULA
a(2*n) = a(n). - Robert Israel, Mar 04 2019
From Amiram Eldar, Feb 21 2021: (Start)
MAPLE
[seq(padic[ordp](combinat:-multinomial(3*n, n, n, n), 2), n=0..128)];
# alternative:
f:= proc(n) local r, t;
t:= 0; r:= 3*n;
while r > 1 do t:= t + floor(r) - 3*floor(r/3); r:= r/2; od;
t
end proc:
map(f, [$0..200]); # Robert Israel, Mar 03 2019
MATHEMATICA
Table[IntegerExponent[(3 n)!/n!^3, 2], {n, 0, 100}] (* Vincenzo Librandi Mar 10 2019 *)
PROG
(PARI) a(n) = valuation((3*n)!/n!^3, 2); \\ Michel Marcus, Mar 04 2019
(Magma) [Valuation(Factorial(3*n)/Factorial(n)^3, 2): n in [0..100]]; // Vincenzo Librandi, Mar 10 2019
(Python)
from math import factorial
def A324466(n): return (~(m:=factorial(3*n)//factorial(n)**3)& m-1).bit_length() # Chai Wah Wu, Jul 07 2022
CROSSREFS
KEYWORD
nonn,look
AUTHOR
N. J. A. Sloane, Mar 02 2019
STATUS
approved