[RandyRep]

Fascinating. Interesting head problem in the morning.

The example at the Discovery site isn't real good, however. There are lots of step-by-step moves that seem superflous.

The abacus that is pictured with 10^1, 10^2, 10^3 etc is a base 10 system and can't be right if it's a base 40 system. That is how a modern person would think of it.

In a base 40 system, there would be places for 40^1, 40^2, 40^3 etc.

As described, it's not a perfect Fibonacci system either -- it should be 1, 2, 3, 5, 8, 13, 21, 34, 55, etc. Right?

I can't think in those terms of course, being conditioned over 60 years in base 10. Maybe the Incas could, though! All they would need is names for each Fibo number.

[RightWhale]

1, 2, 3, 5, 8, 13, 21, 34, 55

A rabbit pair begins with 1, so the series begins with another 1. 1, 1, 2, 3, . . ..