login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093527 Denominators of even raw moments in the distribution of line lengths for lines picked at random in the unit disk. 7
1, 1, 3, 2, 5, 1, 7, 4, 9, 5, 11, 3, 13, 7, 1, 8, 17, 3, 19, 1, 7, 11, 23, 2, 25, 13, 27, 1, 29, 15, 31, 16, 11, 17, 5, 9, 37, 19, 39, 2, 41, 1, 43, 11, 1, 23, 47, 4, 49, 25, 17, 13, 53, 9, 55, 7, 19, 29, 59, 5, 61, 31, 21, 32, 13, 1, 67, 17, 23, 7, 71, 2, 73, 37, 5, 19, 1, 13, 79 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..78.

Eric Weisstein's World of Mathematics, Disk Line Picking

FORMULA

a(k) = Denominator[(2*Gamma[3 + n])/((2 + n)*Gamma[2 + n/2]*Gamma[3 + n/2])] for n = 2k.

a(n-1)=numerator(n(n+1)/binomial(2n, n)); a(n)=numerator((n+1)(n+2)/binomial(2(n+1), n+1)); a(n)=numerator(binomial(n+2, 2)/(2binomial(2(n+1), n+1))). - Paul Barry, Sep 11 2004

a(n-1)=numerator(n/C(n)); a(n)=numerator((n+1)/C(n+1)) - Paul Barry, Nov 17 2004

a(n)=denominator(binomial(2n, n)/n). - Enrique Pérez Herrero, Oct 05 2011

a(n)=n/gcd(n,binomial(2n,n)). - Peter Luschny, Oct 05 2011

EXAMPLE

1, 128/(45*Pi), 1, 2048/(525*Pi), 5/3, 16384/(2205*Pi), ...

MAPLE

A093527 := n -> n / igcd(n, binomial(2*n, n)): - Peter Luschny, Oct 05 2011

MATHEMATICA

A093527[n_]:=Denominator[Binomial[2n, n]/n]; Array[A093527, 200] (* Enrique Pérez Herrero, Oct 05 2011 *)

CROSSREFS

Cf. A093070, A093526, A093528, A093529.

Second column of A098505.

Cf. A000108.

Sequence in context: A129538 A076934 A111701 * A088233 A056008 A074830

Adjacent sequences:  A093524 A093525 A093526 * A093528 A093529 A093530

KEYWORD

nonn,frac

AUTHOR

Eric W. Weisstein, Jan 04, 1970

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified October 24 04:24 EDT 2014. Contains 248497 sequences.