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 | 3 |
| 2 | 10 |
| 3 | 33 |
| 4 | 110 |
| 5 | 369 |
| 6 | 1247 |
| 7 | 4245 |
| 8 | 14558 |
| 9 | 50295 |
| 10 | 175029 |
| 11 | 613467 |
| 12 | 2165100 |
| 13 | 7692345 |
| 14 | 27504600 |
| 15 | 98941185 |
| 16 | 357952580 |
| 17 | 1301960925 |
| 18 | 4759282415 |
| 19 | 17478557925 |
| 20 | 64468072820 |
| 21 | 238736987535 |
| 22 | 887359113700 |
| 23 | 3309489922743 |
| 24 | 12381998910700 |
| 25 | 46460457776739 |