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 | 51 |
| 3 | 301 |
| 4 | 1787 |
| 5 | 10619 |
| 6 | 63111 |
| 7 | 375091 |
| 8 | 2229307 |
| 9 | 13249619 |
| 10 | 78747531 |
| 11 | 468026571 |
| 12 | 2781660187 |
| 13 | 16532466059 |
| 14 | 98258743211 |
| 15 | 583989138891 |
| 16 | 3470869901227 |
| 17 | 20628701920939 |
| 18 | 122604233247851 |
| 19 | 728683659684651 |