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 | 11 |
| 3 | 31 |
| 4 | 211 |
| 5 | 851 |
| 6 | 4901 |
| 7 | 22961 |
| 8 | 124531 |
| 9 | 623011 |
| 10 | 3313201 |
| 11 | 17086301 |
| 12 | 90453661 |
| 13 | 473616781 |
| 14 | 2509264811 |
| 15 | 13250049551 |
| 16 | 70368250451 |
| 17 | 373539254611 |
| 18 | 1989045489281 |
| 19 | 10597110956861 |
| 20 | 56566637447401 |
| 21 | 302196871378601 |
| 22 | 1616570627763311 |
| 23 | 8654955238504531 |
| 24 | 46384344189261661 |