This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A056438 #9 Aug 22 2017 20:53:11 %S A056438 0,0,0,0,0,1,1,18,59,630,1681,28867,60083,757577,3514504,21424002, %T A056438 64372109,1024999230,2026631203,26920955243,105501588415,742299898741, %U A056438 1974251382095,31721456317841,74052852505684 %N A056438 Number of step cyclic shifted sequence structures using exactly six different symbols. %C A056438 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 A056438 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 A056438 A056433(n)-A056432(n). %Y A056438 Column 6 of A288627. %Y A056438 Cf. A056419. %K A056438 nonn %O A056438 1,8 %A A056438 _Marks R. Nester_