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 A317201 #5 Feb 12 2021 12:14:03 %S A317201 21,312,1213,213121,3121121312 %N A317201 Reverse of A317199(n). %C A317201 With a different offset, this is F_n in Bo Tan et al., pp. 1706ff. %H A317201 Bo Tan and Zhi-Ying Wen, <a href="http://dx.doi.org/10.1016/j.ejc.2006.07.007">Some properties of the Tribonacci sequence</a>, European Journal of Combinatorics, 28 (2007) 1703-1719. See Prop. 2.8. %Y A317201 Cf. A317199. %K A317201 nonn,more %O A317201 1,1 %A A317201 _N. J. A. Sloane_, Aug 05 2018