A129195 a(n) = denominator(n!/4^n).

1, 4, 8, 32, 32, 128, 256, 1024, 512, 2048, 4096, 16384, 16384, 65536, 131072, 524288, 131072, 524288, 1048576, 4194304, 4194304, 16777216, 33554432, 134217728, 67108864, 268435456, 536870912, 2147483648, 2147483648, 8589934592, 17179869184, 68719476736

Offset

0,2

Links

Table of n, a(n) for n=0..31.

Formula

a(n) = denominator((1/(2*Pi))*int(exp(i*4*t)(-((Pi-t)/i)^n),t,0,2*Pi)), i=sqrt(-1).

a(n) = 2^A092391(n).

Mathematica

Table[Denominator[n!/4^n], {n, 0, 30}] (* Harvey P. Dale, Mar 05 2013 *)

Crossrefs

Cf. A049606, A092391.

Sequence in context: A188117 A094502 A162459 * A180098 A124143 A173617

Adjacent sequences: A129192 A129193 A129194 * A129196 A129197 A129198

Keyword

easy,nonn

Author

Paul Barry, Apr 02 2007

Status

approved