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 A267391 #16 Jan 23 2019 12:18:16
%S A267391 0,0,0,0,0,40,240,1980,18240
%N A267391 Number of elements of S_n with strategic pile of size 5.
%C A267391 Strategic pile is defined in A267323.
%H A267391 K. L. M. Adamyk, E. Holmes, G. R. Mayfield, D. J. Moritz, M. Scheepers, B. E. Tenner, H. C. Wauck, <a href="http://arxiv.org/abs/1410.2353">Sorting Permutations: Games, Genomes, and Cycles</a>, arXiv:1410.2353 [math.CO], 2014-2017.
%H A267391 Marisa Gaetz, Bethany Flanagan, Marion Scheepers, Meghan Shanks, <a href="https://arxiv.org/abs/1811.11937">Quantifying CDS Sortability of Permutations by Strategic Pile Size</a>, arXiv:1811.11937 [math.CO], 2018.
%e A267391 P = [7, 1, 5, 6, 2, 4, 3] has strategic pile size 5. The composition (0,3,4,2,6,5,1,7)(0,1,2,3,4,5,6,7) has cycle (7,3,2,4,1,6,0), and so the strategic pile of P is {1,2,3,4,6}.
%Y A267391 A267323 gives the corresponding sequence for strategic piles of size 3.
%Y A267391 A267324 gives the corresponding sequence for strategic piles of size 4.
%K A267391 nonn,more
%O A267391 1,6
%A A267391 _Marion Scheepers_, Jan 13 2016