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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

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

A055990 as a simple table

n a(n)
1 1
2 4
3 14
4 50
5 181
6 657
7 2385
8 8657
9 31422
10 114051
11 413966
12 1502555
13 5453761
14 19795288
15 71850128
16 260791401
17 946583628
18 3435774958
19 12470688498
20 45264335853
21 164294064481
22 596331286321
23 2164478699633
24 7856317702310

[1,4,14,50,181,657,2385,8657,31422,114051,413966,
 1502555,5453761,19795288,71850128,260791401,
 946583628,3435774958,12470688498,45264335853,
 164294064481,596331286321,2164478699633,
 7856317702310]

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 December 18 23:46 EST 2018. Contains 318245 sequences. (Running on oeis4.)