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%I M2357 N0933 #24 Jan 29 2022 01:01:07
%S 1,1,3,4,9,14,27,48,93,163,315,576,1085
%N Number of period-n solutions to a certain "universal" equation related to transformations on the unit interval.
%C a(n) <= A000048(n), since the solutions counted here are a subset of the solutions counted by A000048 (called U sequence in the paper). The observed equality for prime n means that there are in this case no harmonics, which would disappear. - _M. F. Hasler_, Nov 05 2014
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H N. Metropolis, M. L. Stein and P. R. Stein, <a href="http://dx.doi.org/10.1016/0097-3165(73)90033-2">On finite limit sets for transformations on the unit interval</a>, J. Combin. Theory, A 15 (1973), 25-44; reprinted in P. Cvitanovic, ed., Universality in Chaos, Hilger, Bristol, 1986, pp. 187-206.
%H P. R. Stein, <a href="/A000048/a000048.pdf">Letter to N. J. A. Sloane, Jun 02 1971</a>
%Y Cf. A000048, A001372.
%K nonn,nice,more
%O 3,3
%A _N. J. A. Sloane_