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 | 2 |
| 2 | 9 |
| 3 | 31 |
| 4 | 109 |
| 5 | 339 |
| 6 | 1043 |
| 7 | 2998 |
| 8 | 8406 |
| 9 | 22652 |
| 10 | 59521 |
| 11 | 151958 |
| 12 | 379693 |
| 13 | 927622 |
| 14 | 2224235 |
| 15 | 5236586 |
| 16 | 12130780 |
| 17 | 27669593 |
| 18 | 62229990 |
| 19 | 138095696 |
| 20 | 302673029 |
| 21 | 655627975 |
| 22 | 1404599867 |
| 23 | 2977831389 |
| 24 | 6251060785 |
| 25 | 12999299705 |
| 26 | 26791990052 |
| 27 | 54750235190 |
| 28 | 110977389012 |