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 | 140 |
| 2 | 5673 |
| 3 | 89520 |
| 4 | 790425 |
| 5 | 4756140 |
| 6 | 21841937 |
| 7 | 82112704 |
| 8 | 264639729 |
| 9 | 754898668 |
| 10 | 1950230969 |
| 11 | 4641494832 |
| 12 | 10309971465 |
| 13 | 21592075596 |
| 14 | 42980713761 |
| 15 | 81851507456 |
| 16 | 149924818657 |
| 17 | 265300850124 |
| 18 | 455235310153 |
| 19 | 759857498672 |
| 20 | 1237071456633 |
| 21 | 1968924291180 |
| 22 | 3069774212913 |
| 23 | 4696644466368 |