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 | 6 |
| 2 | 36 |
| 3 | 206 |
| 4 | 1146 |
| 5 | 6258 |
| 6 | 33728 |
| 7 | 180018 |
| 8 | 953628 |
| 9 | 5021698 |
| 10 | 26315676 |
| 11 | 137350746 |
| 12 | 714455826 |
| 13 | 3705635646 |
| 14 | 19171860336 |
| 15 | 98973407550 |
| 16 | 509963556330 |
| 17 | 2623133951730 |
| 18 | 13472299015580 |
| 19 | 69098721151530 |
| 20 | 353966981339070 |
| 21 | 1811212435206070 |
| 22 | 9258333786967920 |
| 23 | 47281424213258070 |