%I #6 Aug 22 2017 20:53:11
%S 0,0,1,4,8,49,54,280,524,2362,2872,22694,21866,131696,298783,904634,
%T 1341518,10744516,10748218,72886710,145274501,522816718,713023210,
%U 5892611212,7059926597,35300963684,70604007679
%N Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly three different symbols.
%C See A056371 for an explanation of step shifts. Permuting the symbols will not change the structure.
%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 A056402(n)-A056401(n).
%Y Cf. A056387.
%K nonn
%O 1,4
%A _Marks R. Nester_