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 | 25 |
| 2 | 1525 |
| 3 | 22518 |
| 4 | 168151 |
| 5 | 837339 |
| 6 | 3186448 |
| 7 | 10011291 |
| 8 | 27249052 |
| 9 | 66342043 |
| 10 | 147745544 |
| 11 | 305902286 |
| 12 | 596046447 |
| 13 | 1103240376 |
| 14 | 1954087550 |
| 15 | 3331605615 |
| 16 | 5493783665 |
| 17 | 8796388244 |
| 18 | 13720622866 |
| 19 | 20906286173 |
| 20 | 31191114176 |
| 21 | 45657032334 |