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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 35 |
| 5 | 125 |
| 6 | 460 |
| 7 | 1747 |
| 8 | 6830 |
| 9 | 27502 |
| 10 | 113987 |
| 11 | 485971 |
| 12 | 2129956 |
| 13 | 9591009 |
| 14 | 44341610 |
| 15 | 210345962 |
| 16 | 1023182861 |
| 17 | 5100235807 |
| 18 | 26035673051 |
| 19 | 136023990102 |
| 20 | 726877123975 |
| 21 | 3970461069738 |
| 22 | 22156281667277 |
| 23 | 126234185382902 |
| 24 | 733899631974167 |
| 25 | 4351500789211840 |