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.

0, 1, 3, 7, 13, 27, 55, 109, 219, 437, 875, 1751, 3501, 7003, 14005, 28011, 56021, 112043, 224085, 448171, 896341, 1792683, 3585365, 7170731, 14341463, 28682925, 57365851, 114731701, 229463403, 458926805, 917853611, 1835707221

Offset: 0

Author

Aviezri S. Fraenkel, Mar 12 2003

Keywords

• nonn

Comments

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

The sequence A_n is given in A080240.

Links

• A. S. Fraenkel, Home Page
• A. S. Fraenkel, New games related to old and new sequences, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 4, Paper G6, 2004.

Crossrefs

Cf. A080240.

Extensions

More terms from John W. Layman, May 04 2004