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 | 15 |
| 5 | 42 |
| 6 | 106 |
| 7 | 280 |
| 8 | 702 |
| 9 | 1778 |
| 10 | 4398 |
| 11 | 10910 |
| 12 | 26678 |
| 13 | 65172 |
| 14 | 157656 |
| 15 | 380524 |
| 16 | 912846 |
| 17 | 2185906 |
| 18 | 5216588 |
| 19 | 12433166 |
| 20 | 29564544 |
| 21 | 70189672 |
| 22 | 166245574 |
| 23 | 392909240 |
| 24 | 926290066 |
| 25 | 2178881218 |
| 26 | 5114469170 |
| 27 | 11985221654 |
| 28 | 28049398284 |
| 29 | 65588182636 |
| 30 | 153277006212 |
| 31 | 358073997608 |