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 | 4 |
| 2 | 11 |
| 3 | 27 |
| 4 | 66 |
| 5 | 170 |
| 6 | 471 |
| 7 | 1398 |
| 8 | 4381 |
| 9 | 14282 |
| 10 | 47897 |
| 11 | 164012 |
| 12 | 570639 |
| 13 | 2010678 |
| 14 | 7158569 |
| 15 | 25709157 |
| 16 | 93020112 |
| 17 | 338736224 |
| 18 | 1240496193 |
| 19 | 4565563209 |
| 20 | 16878057692 |
| 21 | 62644246662 |
| 22 | 233346693759 |
| 23 | 872045012633 |
| 24 | 3268643350608 |
| 25 | 12285088109136 |
| 26 | 46288732360369 |
| 27 | 174813127020311 |
| 28 | 661606223839322 |