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 A056407 #6 Aug 22 2017 20:53:11 %S A056407 0,0,1,4,8,49,54,280,524,2362,2872,22694,21866,131696,298783,904634, %T A056407 1341518,10744516,10748218,72886710,145274501,522816718,713023210, %U A056407 5892611212,7059926597,35300963684,70604007679 %N A056407 Number of primitive (aperiodic) step shifted (decimated) sequence structures using exactly three different symbols. %C A056407 See A056371 for an explanation of step shifts. Permuting the symbols will not change the structure. %D A056407 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 A056407 A056402(n)-A056401(n). %Y A056407 Cf. A056387. %K A056407 nonn %O A056407 1,4 %A A056407 _Marks R. Nester_