login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


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

A121257 as a simple table

n a(n)
1 4
2 20
3 76
4 260
5 840
6 2616
7 7940
8 23644
9 69380
10 201220
11 578064
12 1647600
13 4664836
14 13132580
15 36789820
16 102621956
17 285174360
18 789810984
19 2180889860
20 6005842540
21 16498958324
22 45225010180
23 123715684896
24 337806904800
25 920819997700

[4,20,76,260,840,2616,7940,23644,69380,201220,
 578064,1647600,4664836,13132580,36789820,
 102621956,285174360,789810984,2180889860,
 6005842540,16498958324,45225010180,123715684896,
 337806904800,920819997700]

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 27 07:02 EDT 2021. Contains 347673 sequences. (Running on oeis4.)