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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130546 Denominators of 2*sum(1/binomial(2*k,k),k=1..n), n>=1. 1
1, 3, 30, 210, 315, 6930, 16380, 60060, 1021020, 19399380, 461890, 37182145, 106234700, 75482550, 166363540200, 5157269746200, 1719089915400, 12033629407800, 445244288088600, 445244288088600, 588871477794600 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Numerators are given by A130545.

For the rationals r(n):= 2*sum(1/binomial(2*k,k),k=1..n), n>=1, the Comtet reference and a W. Lang link see A130545.

FORMULA

a(n)=denom(r(n)), n>=1.

CROSSREFS

Sequence in context: A003771 A121100 A203366 * A051133 A043030 A178015

Adjacent sequences:  A130543 A130544 A130545 * A130547 A130548 A130549

KEYWORD

nonn,frac,easy

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de) Jul 13 2007

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

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

Last modified February 15 04:59 EST 2012. Contains 205694 sequences.