Mystery sequence in Dec. MAA Focus Magazine

[N. J. A. Sloane]

what is the geometric relationship between the places of 20 and 202?

the photo isn't clear enough to answer that.  a web search might reveal it?

the numbers are written in arabic in the form used in Mughal India,
and the faces are triangular, so there are three possible
orientations for each symbol.  in the photo printed in Focus,
I can only make out 61 for certain.

It was on sale at Sotheby's in London in May 2005 as part of the
Exotica - East meets West 1500-1900 sale, so there may be information of the web.

njas