%I #9 Aug 22 2017 20:53:11

%S 0,0,0,0,0,1,1,18,59,630,1681,28867,60083,757577,3514504,21424002,

%T 64372109,1024999230,2026631203,26920955243,105501588415,742299898741,

%U 1974251382095,31721456317841,74052852505684

%N Number of step cyclic shifted sequence structures using exactly six different symbols.

%C See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. 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 A056433(n)-A056432(n).

%Y Column 6 of A288627.

%Y Cf. A056419.

%K nonn

%O 1,8

%A _Marks R. Nester_