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 A056448 #6 Aug 22 2017 20:53:12 %S A056448 0,0,0,0,0,1,1,18,59,630,1681,28866,60083,757576,3514504,21423984, %T A056448 64372109,1024999170,2026631203,26920954613,105501588414,742299897060, %U A056448 1974251382095,31721456288956,74052852505684 %N A056448 Number of primitive (period n) step cyclic shifted sequence structures using exactly six different symbols. %C A056448 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 A056448 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 A056448 A056443(n)-A056442(n). %Y A056448 Cf. A056428. %K A056448 nonn %O A056448 1,8 %A A056448 _Marks R. Nester_