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 | 9 |
| 1 | 19 |
| 2 | 351 |
| 3 | 721 |
| 4 | 13329 |
| 5 | 27379 |
| 6 | 506151 |
| 7 | 1039681 |
| 8 | 19220409 |
| 9 | 39480499 |
| 10 | 729869391 |
| 11 | 1499219281 |
| 12 | 27715816449 |
| 13 | 56930852179 |
| 14 | 1052471155671 |
| 15 | 2161873163521 |
| 16 | 39966188099049 |
| 17 | 82094249361619 |
| 18 | 1517662676608191 |