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.
| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 13471118294776123 |
| 3 | 134711182947761231993225218431364220735715778934915127244763960364079103682167761271443439204710647114985118604983010349 |