The Integer Sequence defined by the Recurrence Relation
See also Perrin Sequence, Plastic Constant
References
Sloane, N. J. A. Sequence
A000931/M0284
in ``An On-Line Version of the Encyclopedia of Integer Sequences.''
http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.
The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
Stewart, I. ``Tales of a Neglected Number.'' Sci. Amer. 274, 102-103, June 1996.