

A081482


Consider the mapping f(a/b) = (a^3 +b^3)/(a^2+b^2). Taking a =1, b = 2 to start with and carrying out this mapping repeatedly on each new (reduced) rational number gives the following sequence 1/2,9/5,427/53,39001680/92569,... Sequence contains the denominators.


1



2, 5, 53, 92569, 1521139611842161, 1759826706496123129893760473796973076447567001, 5450165776683729363553774731808009059782198745252457060273092560160498157854877231868041524958184901475157837190479609639387791150077013
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

The mapping f(a/b) = (a + b)/(a  b). Taking a = 2 b = 1 to start with and carrying out this mapping repeatedly on each new (reduced)rational number gives the periodic sequence 2/1,3/1,2/1,3/1,...


LINKS



CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003


STATUS

approved



