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 | 3 |
| 3 | 9 |
| 4 | 53 |
| 5 | 79 |
| 6 | 159 |
| 7 | 237 |
| 8 | 477 |
| 9 | 711 |
| 10 | 4187 |
| 11 | 12561 |
| 12 | 37683 |
| 13 | 265371653 |
| 14 | 796114959 |
| 15 | 2388344877 |
| 16 | 14064697609 |
| 17 | 20964360587 |
| 18 | 42194092827 |
| 19 | 62893081761 |
| 20 | 126582278481 |
| 21 | 188679245283 |
| 22 | 1111111111111 |
| 23 | 3333333333333 |
| 24 | 9999999999999 |