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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 76 |
| 6 | 300 |
| 7 | 1189 |
| 8 | 4701 |
| 9 | 18754 |
| 10 | 75243 |
| 11 | 303407 |
| 12 | 1227560 |
| 13 | 4981002 |
| 14 | 20260788 |
| 15 | 82579632 |
| 16 | 337175123 |
| 17 | 1378826528 |
| 18 | 5646408697 |
| 19 | 23151632776 |
| 20 | 95034718893 |
| 21 | 390504864746 |
| 22 | 1606102645910 |
| 23 | 6611314522432 |
| 24 | 27235758104621 |
| 25 | 112279739875866 |