T2(x) = -x: Difference between revisions

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A more colourful display of this sequence can be found [http://thomas1111.wordpress.com/2010/01/10/a-sequence-of-584-elements-with-t2x-tx/ on this page].
A more colourful display of this sequence can be found [http://thomas1111.wordpress.com/2010/01/10/a-sequence-of-584-elements-with-t2x-tx/ on this page].
This sequence has various multiplicative properties that are not implied by the basic constraint. Writing <math>a=\pm b</math> to mean that the beginning of the a-sequence closely resembles the beginning of the b-sequence, we have the following relationships: 2=5=17, 3=-15, 7=-9, 11=-13. In addition, the 3-sequence starts pretty similarly to the 13-sequence, and consequently the 11-sequence starts pretty similarly to the 15-sequence.

Revision as of 11:20, 10 January 2010

This sequence, of length [math]\displaystyle{ 594 }[/math], satisfies [math]\displaystyle{ x_{2n} = -x_n }[/math] for all [math]\displaystyle{ n }[/math]:

0+--+-++--+--+-++-++--+-++--+--+-++
--+-++-+--++--+-++-++--+-++--+--+-+
+-++--+--+-++--++++--+--+-++-++----
+++-+--+-++--+--+-++-++--+-++-++--+
-++--+--+-++--+-++-++--+--+-++-+-+-
+--+++---+-++-++--+--+--+-++-+++-+-
---+-+++-++-+---+--+-++-++--+++---+
--+-+++-+--+-++-++--+-++--+--+-++-+
+----++-++--+-++--+--+-++-++--++-+-
++--+--+-++-++-+---+--+-++--++--++-
-++-++---+-++-+-++-++--+-++--+--+-+
+--+-++--+-++-++--+--+--+-+-++--++-
+-+-++--++-+-+--+--+-++--++++-+---+
-++-++--+-++--+--+++--+---++-+++--+
+-+---++-+-+--++--+++---++-+-++--+-
-+-++--++---++-++--+-+--+++-+-++---
-++++-+-+--+--++---++++--++--+-++-+

Here's one of length [math]\displaystyle{ 584 }[/math], which held the record for about ten minutes:

0+--+-++--++---++-+--+-++++-+--+-++---+-++--+
+-+-+-+-++---+-++--++---++-+++---++-+--+++---
-++--+++-++---+--+-++++-+---+--+-++-++---++-+
++--+--+--+-+-++-+++----+++--+-++-+-+--+++-+-
+----++-+--+-+-+++-+-++-+-+---+-+--+++-+-+-+-
-++--+++-+---+++--++--+-++--+--+-+-++-+--++-+
-+--+++---+++---+++--++--++----+++-+---++-+-+
++--+---++-+--+++-+--++--++--+++--+-+--++--++
-++-+-+-+--+--++--+++--++---++---+-+++-++--+-
-++--++--+-+++--++--++-+--+-+-++---++-++---++
+----++-++-+-+-++--++-+-+--+-+--+-+--+-++-++-
++--+--+-+--++-++--++--++-+-++---+++--+--++-+
+---+++--+-+--+-+-++-+-+-++-+-+--+-+--+-++---

A more colourful display of this sequence can be found on this page.

This sequence has various multiplicative properties that are not implied by the basic constraint. Writing [math]\displaystyle{ a=\pm b }[/math] to mean that the beginning of the a-sequence closely resembles the beginning of the b-sequence, we have the following relationships: 2=5=17, 3=-15, 7=-9, 11=-13. In addition, the 3-sequence starts pretty similarly to the 13-sequence, and consequently the 11-sequence starts pretty similarly to the 15-sequence.