An addition chain for which there is a subset 
of members such that each member of
the chain uses the largest element of 
which is less than the member.
Hansen Chain
See also
Addition Chain, Brauer Chain, Hansen NumberExplore with Wolfram|Alpha
References
Guy, R. K. "Addition Chains. Brauer Chains. Hansen Chains." §C6 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 111-113, 1994.Referenced on Wolfram|Alpha
Hansen ChainCite this as:
Weisstein, Eric W. "Hansen Chain." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HansenChain.html