The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #7 Apr 11 2012 10:05:09
%S 1,2,2,3,3,4,3,4,4
%N Length of shortest Lucas chain for n.
%C This may already be in the OEIS - the reference does not give enough terms to check. It would also be nice to give the definition here.
%C Lucas chains are addition chains with additional requirements on the presence of differences between members of the chain. Therefore a(n) >= A003313(n) and A104892(n) <= A003064(n). Shortest simple Lucas chains are constrained even further (forbid duplication between adjacent members). Therefore a(n) <= A105195(n). - _R. J. Mathar_, May 24 2008
%H Daniel Bleichenbacher, <a href="http://www.bell-labs.com/user/bleichen/diss/thesis.html">Efficiency and Security of Cryptosystems based on Number Theory.</a> PhD Thesis, Diss. ETH No. 11404, Zuerich 1996. See p. 64.
%H <a href="/index/Com#complexity">Index to sequences related to the complexity of n</a>
%Y Cf. A104892, A105195, A003313.
%K nonn
%O 2,2
%A _N. J. A. Sloane_, May 23 2008