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 A112684 #11 Jul 09 2025 04:25:30 %S A112684 1,8,22,45,138,415,916,3998,13142,38763,60718,44686,121298,2068731, %T A112684 11214378,25158877,3909879,299954193,977046702,3028468981,1107563239, %U A112684 2983913960,91973871622 %N A112684 Similar to A112683, but using the recurrence x(i) = x(i-1)^2 + x(i-n) mod 3. %D A112684 Terms computed by Bob Harder. %H A112684 Steven R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/csolve/seqmod3.pdf">Periodicity in Sequences Mod 3</a> [Broken link] %H A112684 Steven R. Finch, <a href="https://web.archive.org/web/20150911081920/http://www.people.fas.harvard.edu/~sfinch/csolve/seqmod3.pdf">Periodicity in Sequences Mod 3</a> [From the Wayback machine] %K A112684 nonn %O A112684 1,2 %A A112684 _N. J. A. Sloane_, Dec 31 2005 %E A112684 Broken links corrected by _Steven Finch_, Jan 26 2009