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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 22 |
| 6 | 57 |
| 7 | 155 |
| 8 | 435 |
| 9 | 1249 |
| 10 | 3645 |
| 11 | 10770 |
| 12 | 32143 |
| 13 | 96747 |
| 14 | 293359 |
| 15 | 895373 |
| 16 | 2748803 |
| 17 | 8483035 |
| 18 | 26302248 |
| 19 | 81896176 |
| 20 | 255967640 |
| 21 | 802790415 |
| 22 | 2525691721 |
| 23 | 7968972542 |
| 24 | 25209580699 |
| 25 | 79942927651 |
| 26 | 254077293876 |
| 27 | 809192984902 |
| 28 | 2582113984084 |
| 29 | 8254273128869 |