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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137343 Number of elements of length n with respect to the natural metric in the special group of rational series over the finite field F_2 in two non-commuting variables. 1
1, 12, 1296, 505536, 679848192, 3248147205120, 57637071142391808, 3930578658351563587584, 1050888530707010579202637824, 1112792971262327168651248131637248 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Roland Bacher, Apr 08 2008, Table of n, a(n) for n = 0..14

R. Bacher, The special subgroup of invertible non-commutative rational power series as a metric group, arXiv:0804.1092

FORMULA

The reference contains a somewhat complicated formula.

CROSSREFS

Sequence in context: A078296 A239164 A209176 * A133461 A246981 A174745

Adjacent sequences:  A137340 A137341 A137342 * A137344 A137345 A137346

KEYWORD

nonn

AUTHOR

Roland Bacher, Apr 08 2008

STATUS

approved

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 March 25 12:11 EDT 2019. Contains 321470 sequences. (Running on oeis4.)