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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 14 |
| 4 | 50 |
| 5 | 178 |
| 6 | 644 |
| 7 | 2347 |
| 8 | 8624 |
| 9 | 31908 |
| 10 | 118768 |
| 11 | 444308 |
| 12 | 1669560 |
| 13 | 6298280 |
| 14 | 23842032 |
| 15 | 90531032 |
| 16 | 344702646 |
| 17 | 1315726218 |
| 18 | 5033357852 |
| 19 | 19294463682 |
| 20 | 74099098212 |
| 21 | 285056401796 |
| 22 | 1098314920968 |
| 23 | 4237879802726 |
| 24 | 16373796107092 |
| 25 | 63341371265892 |
| 26 | 245315823125496 |