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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 7 |
| 6 | 8 |
| 7 | 45 |
| 8 | 96 |
| 9 | 258 |
| 10 | 1260 |
| 11 | 2511 |
| 12 | 12594 |
| 13 | 35799 |
| 14 | 126043 |
| 15 | 482640 |
| 16 | 1487929 |
| 17 | 6012740 |
| 18 | 20051360 |
| 19 | 74529198 |
| 20 | 276148256 |
| 21 | 977824914 |
| 22 | 3744986184 |
| 23 | 13527623583 |
| 24 | 50997301218 |
| 25 | 190934525258 |
| 26 | 711190503929 |
| 27 | 2707743977818 |
| 28 | 10155615925523 |
| 29 | 38691707792278 |