%I #6 Mar 30 2012 18:35:35
%S 1,1,3,9,34,125,459,1715,6432,24300,92375,352715,1352034,5200299,
%T 20058297,77558625,300540160,1166803109,4537567188,17672631899,
%U 68923264250,269128935495,1052049481857,4116715363799,16123801834656
%N Number of 2n-bead black-white reversible strings with n black beads and fundamental period 2n.
%F Moebius transform of A032123(n+1) (Christian Bower).
%K nonn
%O 0,3
%A _David W. Wilson_