A080241 - OEIS

A080241

Define two sequences by A_n = mex{A_i,B_i : 0 <= i < n} for n >= 0, B_0=0, B_1=1 and for n >= 2, B_n = 2B_{n-1}+(-1)^{A_n}. Sequence gives B_n.

%I #13 Mar 10 2015 04:41:07

%S 0,1,3,7,13,27,55,109,219,437,875,1751,3501,7003,14005,28011,56021,

%T 112043,224085,448171,896341,1792683,3585365,7170731,14341463,

%U 28682925,57365851,114731701,229463403,458926805,917853611,1835707221

%N Define two sequences by A_n = mex{A_i,B_i : 0 <= i < n} for n >= 0, B_0=0, B_1=1 and for n >= 2, B_n = 2B_{n-1}+(-1)^{A_n}. Sequence gives B_n.

%C The minimal excluded value of set of nonnegative numbers S is mex S = least nonnegative integer not in S.

%C The sequence A_n is given in A080240.

%H A. S. Fraenkel, <a href="http://www.wisdom.weizmann.ac.il/~fraenkel/">Home Page</a>

%H A. S. Fraenkel, <a href="http://www.emis.de/journals/INTEGERS/papers/eg6/eg6.Abstract.html">New games related to old and new sequences</a>, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 4, Paper G6, 2004.

%Y Cf. A080240.

%K nonn

%O 0,3

%A _Aviezri S. Fraenkel_, Mar 12 2003

%E More terms from _John W. Layman_, May 04 2004