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 A056380 #7 Aug 22 2017 20:53:10 %S A056380 0,0,0,0,0,360,2520,48060,317520,4109040,12923136,238785300,559279980, %T A056380 7612396920,37864711260,246263046840,787758864480,13282478342640, %U A056380 27723264985920,387585098313300,1595144664456720 %N A056380 Number of step shifted (decimated) sequences using exactly six different symbols. %C A056380 See A056371 for an explanation of step shifts. %D A056380 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 A056380 A056375(n)-6*A056374(n)+15*A056373(n)-20*A056372(n)+15*A056371(n)-6. %Y A056380 Cf. A056375. %K A056380 nonn %O A056380 1,6 %A A056380 _Marks R. Nester_