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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 25 |
| 6 | 77 |
| 7 | 247 |
| 8 | 801 |
| 9 | 2657 |
| 10 | 8969 |
| 11 | 30635 |
| 12 | 105785 |
| 13 | 368745 |
| 14 | 1295493 |
| 15 | 4582767 |
| 16 | 16309953 |
| 17 | 58357313 |
| 18 | 209798289 |
| 19 | 757461011 |
| 20 | 2745281705 |
| 21 | 9984464761 |
| 22 | 36428252541 |
| 23 | 133293594343 |
| 24 | 489028250465 |
| 25 | 1798543861537 |
| 26 | 6629635284505 |