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 A056419 #6 Aug 22 2017 20:53:11 %S A056419 0,0,0,0,0,60,360,6030,35280,410976,1174896,19948200,43022700, %T A056419 543757860,2524673904,15399118440,46338868800,737917466160, %U A056419 1459120076400,19381180990752,75959665269840,534453892557660 %N A056419 Number of step cyclic shifted sequences using exactly six different symbols. %C A056419 See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. %D A056419 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 A056419 A056414(n)-6*A056413(n)+15*A056412(n)-20*A056411(n)+15*A002729(n)-6. %Y A056419 Cf. A056414. %K A056419 nonn %O A056419 1,6 %A A056419 _Marks R. Nester_