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 A321008 #16 Apr 10 2019 01:25:26 %S A321008 1,2,6,24,120,720,54,432,3,30,0 %N A321008 a(1)=1; thereafter a(n) is obtained by applying Eric Angelini's remove-repeated-digits map, x->A320486(x), to n*a(n-1), stopping when 0 is reached. %D A321008 Eric Angelini, Posting to Sequence Fans Mailing List, Oct 24 2018 %H A321008 N. J. A. Sloane, Coordination Sequences, Planing Numbers, and Other Recent Sequences (II), Experimental Mathematics Seminar, Rutgers University, Jan 31 2019, <a href="https://vimeo.com/314786942">Part I</a>, <a href="https://vimeo.com/314790822">Part 2</a>, <a href="https://oeis.org/A320487/a320487.pdf">Slides.</a> (Mentions this sequence) %e A321008 a(6)=720, so for a(7) we compute 7*720 = 5040 which becomes 54 = a(7). %Y A321008 Cf. A320485, A320486, A321009. %K A321008 nonn,base,fini,full %O A321008 1,2 %A A321008 _N. J. A. Sloane_, Nov 03 2018