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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

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

A039991 as a triangular array

1
10
20-1
40-30
80-801
160-20050
320-480180-1
640-1120560-70
1280-25601600-3201
2560-57604320-120090
5120-1280011200-4000500-1
10240-2816028160-12320220

A039991 as a square array

112481632641282565121024
00000000000
-1-3-8-20-48-112-256-576-1280-2816
000000000
15185616043211202816
0000000
-1-7-32-120-400-1232
00000
1950220
00
-1

A039991 as an upper right triangle

112481632641282565121024
00000000000
-1-3-8-20-48-112-256-576-1280-2816
000000000
15185616043211202816
0000000
-1-7-32-120-400-1232
00000
1950220
00
-1

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 10 12:22 EST 2019. Contains 329895 sequences. (Running on oeis4.)