COMMENT FROM M. F. Hasler RE A001045

[Maximilian Hasler]

(This is: Jacobsthal sequence: a(n) = a(n-1) + 2a(n-2), with a(0) = 0,
a(1) = 1.)

%I A001045
%S A001045 0,1,1,3,5,11,21,43,85,171,341,683,1365,2731,5461,10923,21845,43691
%C A001045 From a(2) on (i.e., 1,3,5,11,21,...) also: least odd number
such that the subsets of {a(2),...,a(n)} sum to 2^(n-1) different
values, cf. A138000 and A064934. It is interesting to note the pattern
of numbers occuring (or not occuring) as such a sum (A003158).
%Y A001045 Cf. A138000, A064934, A003158.
%K A001045 nonn,nice,easy,core
%O A001045 0
%A A001045 M. F. Hasler (www.univ-ag.fr/~mhasler), Apr 09 2008