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This page contains notes about the status of the OEIS wiki. It provides a brief description of the wiki setup. It will also be used to announce changes in the structure of the wiki, so it may be useful to add it to your watchlist by clicking on the watch tab at the top of the page.

Users can create and modify discussion pages here. The discussion pages are a reasonable place to make comments about the structure of the wiki.

Do not use the discussion pages to suggest changes to OEIS sequence entries.

An account is necessary to contribute to the Wiki. To request an account, click here. There was a time when the username was required to be your Real Name. This is no longer required, but is strongly recommended. If this evolving statement causes you to want to change your username, send email to David, and I can make the change.

A few preliminary pages (most of these need to be updated!)

Sequence of the Day for August 11

A001020:
11n, n   ≥   0
.
{ 1, 11, 121, 1331, 14641, 161051, 1771561, ... }

In the classic Star Trek episode “The Trouble with Tribbles,” Spock estimates the growth of the Tribble population aboard the Enterprise thus: “1,771,561. That’s assuming one tribble, multiplying with an average litter of 10, producing a new generation every 12 hours over a period of three days.”

Note that for
n = 0
to 4 you get numbers which are concatenated single digit (base 10) binomial coefficients, while for
n   ≥   5
some binomial coefficients are now more than single digit (base 10) and thus overlap, e.g.
1 
 5 
 10
  10
    5
     1
------
161051
Setting
x = 10
and
y = 1
in
(x + y)n =
n
k   = 0
  
(  nk  ) xk yn  − k

explains why this is so.

See also:

* A096884
101n, n   ≥   0
.
* A097659
1001n, n   ≥   0
.