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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 19 |
| 6 | 91 |
| 7 | 177 |
| 8 | 3641 |
| 9 | 28673 |
| 10 | 28319 |
| 11 | 2523223 |
| 12 | 27526069 |
| 13 | 109339663 |
| 14 | 4239014627 |
| 15 | 59043418019 |
| 16 | 26718637649 |
| 17 | 14052333488521 |
| 18 | 238063061452591 |
| 19 | 158218865944829 |
| 20 | 7358312808534631 |
| 21 | 124213980448686521 |
| 22 | 11277840764547411113 |
| 23 | 67527236643922308689 |