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%I #5 Feb 21 2023 23:33:53
%S 0,2,1,1,1,2,4,16,40,512,1472,65536
%N Number of pair-exchange / set-rotate sequences achieving the minimum length of A048200(n).
%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a061/A061545.java">Java program</a> (github)
%e Let "r" denote rotation and "x" an exchange.
%e For n = 5, the shortest sequence reversing "ABCDE" has length A048200(5) = 10, the only sequence doing so is "xrrxrrxrxr", so a(5) = 1.
%e For n = 6, we have A048200(6) = 15, but there are 2 solutions of this length "xrxrrxrxrrxrrrx" and "rxrrxrxrrxrxrrx", so a(6) = 2.
%Y Cf. A048200.
%K more,nonn
%O 1,2
%A _Naohiro Nomoto_, May 16 2001
%E Sequence revised and a(9)-a(12) from _Sean A. Irvine_, Feb 21 2023
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