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

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)

A117998 as a simple table

n a(n)
0 1
1 6
2 20
3 120
4 272
5 1632
6 5440
7 32640
8 65792
9 394752
10 1315840
11 7895040
12 17895424
13 107372544
14 357908480
15 2147450880
16 4295032832
17 25770196992
18 85900656640
19 515403939840
20 1168248930304
21 7009493581824
22 23364978606080

[1,6,20,120,272,1632,5440,32640,65792,394752,
 1315840,7895040,17895424,107372544,357908480,
 2147450880,4295032832,25770196992,85900656640,
 515403939840,1168248930304,7009493581824,
 23364978606080]

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 September 2 12:10 EDT 2014. Contains 246357 sequences.