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 | 17 |
| 3 | 70 |
| 4 | 297 |
| 5 | 1342 |
| 6 | 6519 |
| 7 | 34006 |
| 8 | 189647 |
| 9 | 1125180 |
| 10 | 7070043 |
| 11 | 46861668 |
| 12 | 326509757 |
| 13 | 2384118432 |
| 14 | 18194367189 |
| 15 | 144769455298 |
| 16 | 1198423872693 |
| 17 | 10301330797778 |
| 18 | 91782832060611 |
| 19 | 846291315842738 |
| 20 | 8063691844581123 |
| 21 | 79290580233274024 |
| 22 | 803613726879441863 |
| 23 | 8385262925870388104 |