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 | 9 |
| 2 | 19 |
| 3 | 161 |
| 4 | 341 |
| 5 | 2889 |
| 6 | 6119 |
| 7 | 51841 |
| 8 | 109801 |
| 9 | 930249 |
| 10 | 1970299 |
| 11 | 16692641 |
| 12 | 35355581 |
| 13 | 299537289 |
| 14 | 634430159 |
| 15 | 5374978561 |
| 16 | 11384387281 |
| 17 | 96450076809 |
| 18 | 204284540899 |
| 19 | 1730726404001 |
| 20 | 3665737348901 |
| 21 | 31056625195209 |
| 22 | 65778987739319 |
| 23 | 557288527109761 |
| 24 | 1180356041958841 |
| 25 | 10000136862780489 |