A086117 Denominator of mean deviation of a symmetrical binomial distribution on n elements.

2, 2, 4, 4, 16, 16, 32, 32, 256, 256, 512, 512, 2048, 2048, 4096, 4096, 65536, 65536, 131072, 131072, 524288, 524288, 1048576, 1048576, 8388608, 8388608, 16777216, 16777216, 67108864, 67108864, 134217728, 134217728, 4294967296, 4294967296

Offset

1,1

Comments

Also denominator of x(n)=Sum(x(k)*x(n-k-1):0<=k<n), x(0)=1/2: x(n)=A098597(n)/a(n+2). - Reinhard Zumkeller, Feb 06 2008

Links

Table of n, a(n) for n=1..34.

Eric Weisstein's World of Mathematics, Binomial Distribution

Index to divisibility sequences

Formula

a(1)=2, a(n) = a(n-1)*A006519(n). - Jon Perry, Mar 31 2004

Mathematica

Denominator[Table[If[OddQ[n], n!!/2/(n-1)!!, (n-1)!!/2/(n-2)!! ], {n, 50}]]

Crossrefs

Cf. A086116.

Twice A101926.

Sequence in context: A106051 A066781 A112869 * A095240 A110428 A076928

Adjacent sequences: A086114 A086115 A086116 * A086118 A086119 A086120

Keyword

nonn,frac

Author

Eric W. Weisstein, Jul 10 2003

Status

approved