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 | 5 |
| 3 | 18 |
| 4 | 84 |
| 5 | 311 |
| 6 | 1286 |
| 7 | 4636 |
| 8 | 21607 |
| 9 | 79398 |
| 10 | 328540 |
| 11 | 1183512 |
| 12 | 5518960 |
| 13 | 20382304 |
| 14 | 84281919 |
| 15 | 303834326 |
| 16 | 1416057916 |
| 17 | 5203506983 |
| 18 | 21531002534 |
| 19 | 77561732700 |
| 20 | 361685609752 |
| 21 | 1335790797424 |
| 22 | 5523583535712 |
| 23 | 19912388519360 |
| 24 | 92801359368576 |