A045630 - OEIS

%I #15 Feb 09 2016 09:00:40

%S 1,1,2,9,32,125,450,1715,6400,24300,92250,352715,1351584,5200299,

%T 20056582,77558625,300533760,1166803109,4537542888,17672631899,

%U 68923172000,269128935495,1052049129142,4116715363799,16123800483072

%N Number of 2n-bead black-white complementable strings with n black beads and fundamental period 2n.

%C For n>0, a(n) is divisible by n (cf. A022553), 2*a(n) is divisible by n^2 (cf. A268619), and 12*a(n) is divisible by n^3 (cf. A268592). - _Max Alekseyev_, Feb 07 2016

%F Moebius transform of A001700(n-1). - _Christian G. Bower_.

%F For n>0, a(n) = A007727(n)/2 = n * A022553(n).

%Y Cf. A007727.

%K nonn

%O 0,3

%A _David W. Wilson_