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 | 5 |
| 3 | 15 |
| 4 | 56 |
| 5 | 203 |
| 6 | 749 |
| 7 | 2777 |
| 8 | 10293 |
| 9 | 38240 |
| 10 | 141997 |
| 11 | 527593 |
| 12 | 1960029 |
| 13 | 7282483 |
| 14 | 27057400 |
| 15 | 100531559 |
| 16 | 373522965 |
| 17 | 1387822193 |
| 18 | 5156442953 |
| 19 | 19158736256 |
| 20 | 71184183353 |
| 21 | 264484479633 |
| 22 | 982690786037 |
| 23 | 3651182836279 |
| 24 | 13565952140920 |
| 25 | 50404229548515 |
| 26 | 187276671274621 |