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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 4 |
| 5 | 11 |
| 6 | 28 |
| 7 | 79 |
| 8 | 284 |
| 9 | 1363 |
| 10 | 8356 |
| 11 | 61583 |
| 12 | 523924 |
| 13 | 5024179 |
| 14 | 53479148 |
| 15 | 624890431 |
| 16 | 7946278828 |
| 17 | 109195935539 |
| 18 | 1612048228564 |
| 19 | 25439293045903 |
| 20 | 427278358483556 |
| 21 | 7609502950269523 |
| 22 | 143217213477235804 |
| 23 | 2840152418116022399 |