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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 23 |
| 6 | 59 |
| 7 | 153 |
| 8 | 401 |
| 9 | 1063 |
| 10 | 2847 |
| 11 | 7693 |
| 12 | 20947 |
| 13 | 57413 |
| 14 | 158265 |
| 15 | 438467 |
| 16 | 1220145 |
| 17 | 3408759 |
| 18 | 9556815 |
| 19 | 26878861 |
| 20 | 75815839 |
| 21 | 214411865 |
| 22 | 607827693 |
| 23 | 1726911631 |
| 24 | 4916352891 |
| 25 | 14022750725 |
| 26 | 40066540277 |
| 27 | 114666463855 |
| 28 | 328662240617 |