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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 60 |
| 5 | 275 |
| 6 | 1238 |
| 7 | 5480 |
| 8 | 23922 |
| 9 | 103267 |
| 10 | 441798 |
| 11 | 1876366 |
| 12 | 7921488 |
| 13 | 33275758 |
| 14 | 139194812 |
| 15 | 580180598 |
| 16 | 2410827422 |
| 17 | 9990993443 |
| 18 | 41308185542 |
| 19 | 170439003998 |
| 20 | 701953309592 |
| 21 | 2886284314298 |
| 22 | 11850433719572 |
| 23 | 48591008205608 |
| 24 | 199002198798980 |
| 25 | 814117064956430 |