%I
%S 3,3,7,15,21,79,75,306,433,1605,1695,12662,10461,57759,122791,347895,
%T 476049,3596917,3401967,22005312,41597289,142675887,186077883,
%U 1476684552,1694657979,8147271993,15690973311
%N Number of primitive (period n) step cyclic shifted sequences using a maximum of three different symbols.
%C See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent.
%D M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]
%F Sum mu(d)*A056411(n/d) where dn.
%K nonn
%O 1,1
%A _Marks R. Nester_
