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 | 121 |
| 3 | 14521 |
| 4 | 1742521 |
| 5 | 209102521 |
| 6 | 25092302521 |
| 7 | 3011076302521 |
| 8 | 361329156302521 |
| 9 | 43359498756302521 |
| 10 | 5203139850756302521 |
| 11 | 624376782090756302521 |
| 12 | 74925213850890756302521 |
| 13 | 8991025662106890756302521 |
| 14 | 1078923079452826890756302521 |
| 15 | 129470769534339226890756302521 |