A228449 - OEIS

%I #10 Jun 07 2014 09:02:10

%S 1,0,0,0,0,0,0,0,0,1,3,9,28,92,324,1217,4871,20703,93166,442542,

%T 2212711,11616735,63892044,367379253,2204275523,13776722023,

%U 89548693155,604453678799,4231175751597,30676024199079,230070181493096,1783043906571497,14264351252571976

%N floor(n! / 4^n).

%t Table[Floor[n!/4^n],{n,0,40}] (* _Harvey P. Dale_, Jun 07 2014 *)

%o (Python)

%o import math

%o for n in range(99): print str(math.factorial(n)/(4**n))+',',

%Y Cf. A000142, A066979, A212310.

%K nonn,less

%O 0,11

%A _Alex Ratushnyak_, Oct 27 2013