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 | 37 |
| 3 | 228 |
| 4 | 1404 |
| 5 | 8646 |
| 6 | 53244 |
| 7 | 327888 |
| 8 | 2019204 |
| 9 | 12434688 |
| 10 | 76575456 |
| 11 | 471567960 |
| 12 | 2904015888 |
| 13 | 17883548064 |
| 14 | 110130696144 |
| 15 | 678208272192 |
| 16 | 4176550921536 |
| 17 | 25720089706080 |
| 18 | 158389787869632 |
| 19 | 975398032747008 |
| 20 | 6006708734718528 |
| 21 | 36990591135528960 |