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 A056434 #9 Aug 22 2017 20:53:11 %S A056434 0,1,1,3,2,7,4,13,10,25,14,87,36,129,183,356,260,1345,804,3759,4433, %T A056434 9757,8384,47461,33780,108329,138766,408375,331184,2251815,1155734 %N A056434 Number of step cyclic shifted sequence structures using exactly two different symbols. %C A056434 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 A056434 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 A056434 A056429(n)-1. %Y A056434 Column 2 of A288627. %Y A056434 Cf. A056415. %K A056434 nonn %O A056434 1,4 %A A056434 _Marks R. Nester_