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Number of 2n-bead balanced binary strings, rotationally equivalent to reverse.
6

%I #8 Sep 15 2019 19:57:03

%S 1,2,6,8,38,52,216,268,1062,1232,4956,5524,21848,24000,95780,102808,

%T 410662,437548,1748592,1847524,7384988,7759144,31033404,32449828,

%U 129774936,135207552,540807104,561629852,2246432996,2326762744,9306937416,9617286180,38468731942

%N Number of 2n-bead balanced binary strings, rotationally equivalent to reverse.

%H Andrew Howroyd, <a href="/A045653/b045653.txt">Table of n, a(n) for n = 0..1000</a>

%F Inverse Moebius transform of A045662. - _Andrew Howroyd_, Sep 15 2019

%o (PARI) c(n)={sumdiv(n,d, moebius(d)*d)} \\ A023900

%o a(n)={if(n<1, n==0, 2*sumdiv(n, d, c(n/d) * d * binomial(d-d%2, d\2)))} \\ _Andrew Howroyd_, Sep 15 2019

%Y Cf. A000984, A023900, A045662, A045654, A045655, A045656.

%K nonn

%O 0,2

%A _David W. Wilson_

%E Terms a(30) and beyond from _Andrew Howroyd_, Sep 15 2019