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Number of binary Lyndon words of length n with trace 0 and subtrace 1 over Z_2.
7

%I #17 May 03 2019 07:21:51

%S 0,0,1,1,2,2,4,6,13,24,48,85,160,288,541,1008,1920,3626,6912,13107,

%T 24989,47616,91136,174590,335462,645120,1242904,2396745,4628480,

%U 8947294,17317888,33552384,65074253,126320640,245428574,477218560,928645120,1808400384,3524068955

%N Number of binary Lyndon words of length n with trace 0 and subtrace 1 over Z_2.

%C Same as the number of binary Lyndon words of length n with trace 0 and subtrace 1 over GF(2).

%H Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>

%H F. Ruskey, <a href="http://combos.org/TSlyndonZ2">Binary Lyndon words with given trace and subtrace</a>

%H F. Ruskey, <a href="http://combos.org/TSlyndonF2">Binary Lyndon words with given trace and subtrace over GF(2)</a>

%F a(2n) = A042980(2n), a(2n+1) = A042979(2n+1). This follows from Cattell et al. (see A042979), Main Theorem on p. 33 and Theorem 4 on p. 44.

%e a(5;0,1)=2 since the two binary Lyndon words of trace 0, subtrace 1 and length 5 are { 00011, 00101 }.

%Y Cf. A074027, A074029, A074030.

%K easy,nonn

%O 1,5

%A _Frank Ruskey_ and Nate Kube, Aug 21 2002

%E Terms a(33) onward from _Max Alekseyev_, Apr 09 2013