Shortest Addition Chains
http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html [wwwhomes.uni-bielefeld.de]
2018-02-07 03:10
A finite sequence of positive integers a0, a1, ..., ar is called an addition chain iff for each element ai, but the first a0 which equals 1, there exist elements in the list with smaller indexes j and k such that ai = aj + ak.
Preciser this is called an addition chain of length r for its last number ar. It can be interpreted like calculating n = ar starting from 1 by addition of only previous calculated numbers.
source: trivium