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) |
|---|---|
| 3 | 3 |
| 4 | 16 |
| 5 | 67 |
| 6 | 251 |
| 7 | 888 |
| 8 | 3023 |
| 9 | 10038 |
| 10 | 32722 |
| 11 | 105228 |
| 12 | 334836 |
| 13 | 1056611 |
| 14 | 3311784 |
| 15 | 10322791 |
| 16 | 32026810 |
| 17 | 98974177 |
| 18 | 304835956 |
| 19 | 936147219 |
| 20 | 2867586542 |
| 21 | 8764280567 |
| 22 | 26733395986 |
| 23 | 81399821915 |
| 24 | 247459136331 |
| 25 | 751211286356 |
| 26 | 2277496842016 |