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 | 4 |
| 2 | 23 |
| 3 | 168 |
| 4 | 1473 |
| 5 | 14988 |
| 6 | 173007 |
| 7 | 2228544 |
| 8 | 31636449 |
| 9 | 490102164 |
| 10 | 8219695239 |
| 11 | 148262469336 |
| 12 | 2860241078817 |
| 13 | 58736954622492 |
| 14 | 1278727896354687 |
| 15 | 29406849577341552 |
| 16 | 712119108949808193 |
| 17 | 18108134430393657636 |
| 18 | 482306685868464422391 |
| 19 | 13425231879291031821576 |