[Inverse Add] - A New Kind of Science: The NKS Forum

A New Kind of Science: The NKS Forum

Pages:1



Inverse Add

(Click here to view the original thread with full colors/images)



Posted by: Chris Maes

Reversal Add

Consider the sequence given by

x[n+1] = x[n]+R[x[n],b]

where R[y,b] is the reversal of the digit representation of y in base b, for different initial conditions (integers) x[0].

For instance in base 10, and x[0] = 10 the first five terms in the sequence are

x[0]=10
x[1]=10+01=11
x[2]=11+11=22
x[3]=22+22=44
x[4]=44+44=88
x[5]=88+88=176

In Mathematica this is equivalent to

ReverseAdd[x0_, b_, n_] := 
NestList[(FromDigits[Reverse[IntegerDigits[#, b]], b] + #) &, x0, n]
ReverseAdd[10,10,5]


Wolfram observed that for x[0]=512, no repetitive nature occurred in the base 2 representation of the sequence {x[n]} for the first million iterations.

An earlier initial conditon 271 is equivalent to 512 after 5 iterations. It has been observed that there exits a collection of "attractor" sequences for which many initial conditions converge.





Forum Sponsored by Wolfram Research

© 2004-2009 Wolfram Research, Inc. | Powered by vBulletin 2.3.0 © 2000-2002 Jelsoft Enterprises, Ltd. | Disclaimer
vB Easy Archive Final - Created by Xenon and modified/released by SkuZZy from the Job Openings