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 | 13 |
| 2 | 121 |
| 3 | 1141 |
| 4 | 10131 |
| 5 | 103673 |
| 6 | 975485 |
| 7 | 9403199 |
| 8 | 90862063 |
| 9 | 875241087 |
| 10 | 8427042917 |
| 11 | 81250292031 |
| 12 | 782990517405 |
| 13 | 7544924295103 |
| 14 | 72709571496955 |
| 15 | 700713916141533 |
| 16 | 6752623088862903 |
| 17 | 65073651435105965 |
| 18 | 627109480901081661 |