%I #6 Aug 22 2017 20:53:11
%S 0,0,0,0,0,1,4,83,454,5761,17998,334796,777107,10574991,52611728,
%T 342198939,1094122103,18448004164,38504610244,538330828006,
%U 2215487105213,16330536692133,45407723468330
%N Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly six 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 A056405(n)-A056404(n).
%Y Cf. A056390.
%K nonn
%O 1,7
%A _Marks R. Nester_