%I #6 Aug 22 2017 20:53:10
%S 6,30,120,720,2010,23820,46950,434700,1683450,15126810,36284466,
%T 547180200,1088416050,13060942950,58782162480,352913410080,
%U 1057916846190,16926687985950,33853322280030
%N Number of primitive (aperiodic) step shifted (decimated) sequences using a maximum of six different symbols.
%C See A056371 for an explanation of step shifts.
%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)*A056375(n/d) where d|n.
%K nonn
%O 1,1
%A _Marks R. Nester_