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 | 2 |
| 2 | 57 |
| 3 | 116 |
| 4 | 3305 |
| 5 | 6726 |
| 6 | 191633 |
| 7 | 389992 |
| 8 | 11111409 |
| 9 | 22612810 |
| 10 | 644270089 |
| 11 | 1311152988 |
| 12 | 37356553753 |
| 13 | 76024260494 |
| 14 | 2166035847585 |
| 15 | 4408095955664 |
| 16 | 125592722606177 |
| 17 | 255593541168018 |
| 18 | 7282211875310681 |
| 19 | 14820017291789380 |
| 20 | 422242696045413321 |