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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 21 |
| 6 | 122 |
| 7 | 849 |
| 8 | 6719 |
| 9 | 59873 |
| 10 | 593686 |
| 11 | 6483027 |
| 12 | 77309508 |
| 13 | 999569969 |
| 14 | 13927664613 |
| 15 | 208044077633 |
| 16 | 3316415176712 |
| 17 | 56193522437465 |
| 18 | 1008499234742158 |
| 19 | 19110533105114433 |
| 20 | 381290148293261075 |
| 21 | 7989548583615385153 |
| 22 | 175418232627066361514 |
| 23 | 4027213499971769192903 |
| 24 | 96489861550805864197512 |