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 | 5 |
| 3 | 19 |
| 4 | 129 |
| 5 | 1405 |
| 6 | 18262 |
| 7 | 310347 |
| 8 | 5896728 |
| 9 | 135624240 |
| 10 | 3933101824 |
| 11 | 121926157641 |
| 12 | 4511267827532 |
| 13 | 184961980943493 |
| 14 | 7953365180610401 |
| 15 | 373808163488684050 |
| 16 | 19811832664899731266 |
| 17 | 1168898127229083969893 |
| 18 | 71302785760974119699474 |