%I #5 Jul 16 2017 21:07:00

%S 31,47,62,63,71,79

%N Positive integers n for which the length of shortest addition-subtraction chain is smaller than the length of shortest addition chain, i.e., A128998(n) < A003313(n).

%K nonn,more,hard

%O 1,1

%A _Max Alekseyev_, Sep 27 2013