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 A056436 #9 Aug 22 2017 20:53:11 %S A056436 0,0,0,1,1,11,13,83,162,930,1369,13730,16421,124702,355793,1356781, %T A056436 2555043,25933814,32931815,283330733,720489755,3308255032,5763641923, %U A056436 60874698532,93543112676,600086810852 %N A056436 Number of step cyclic shifted sequence structures using exactly four different symbols. %C A056436 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 A056436 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 A056436 A056431(n)-A056430(n). %Y A056436 Column 4 of A288627. %Y A056436 Cf. A056417. %K A056436 nonn %O A056436 1,6 %A A056436 _Marks R. Nester_