%I #19 Feb 12 2022 18:07:22
%S 1,4,12,54,220,1130,5568,26966,132037,589652,2601811,10147378,
%T 38356054,129698048
%N Number of different Othello shapes at the end of the n-th ply.
%H Alain Brobecker, <a href="http://abrobecker.free.fr/text/othello.pdf">Othello and retrograde analysis (pdf)</a>
%H Alain Brobecker, <a href="http://abrobecker.free.fr/tools/othello.zip">programs to generate sequences</a>
%Y Cf. A124004, A124005, A124006.
%K fini,hard,nonn
%O 0,2
%A _Alain Brobecker_, Dec 30 2006
%E Edited by _Charles R Greathouse IV_, Oct 28 2009
%E a(10)-a(12) from _Dominic Hofer_, Mar 04 2020
%E a(13) from _Dominic Hofer_, Feb 11 2022