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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 1 |
| 9 | 4 |
| 10 | 21 |
| 11 | 266 |
| 12 | 7849 |
| 13 | 367860 |
| 14 | 21609300 |
| 15 | 1470293675 |
| 16 | 113314233808 |
| 17 | 9799685588936 |
| 18 | 945095823831036 |
| 19 | 101114579937187980 |
| 20 | 11945375659139626688 |
| 21 | 1551593789610509806552 |
| 22 | 220716215902792573134799 |
| 23 | 34259321384370620122314325 |
| 24 | 5782740798229825207562109439 |