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 | 1 |
| 2 | 4 |
| 3 | 23 |
| 4 | 159 |
| 5 | 1236 |
| 6 | 10454 |
| 7 | 94401 |
| 8 | 899286 |
| 9 | 8964253 |
| 10 | 92961432 |
| 11 | 998600238 |
| 12 | 11075132605 |
| 13 | 126489183013 |
| 14 | 1484601117235 |
| 15 | 17876874457054 |
| 16 | 220546820252773 |
| 17 | 2784446513061287 |
| 18 | 35940592329823310 |
| 19 | 473893641259375150 |