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 | 1 |
| 2 | 19 |
| 3 | 342 |
| 4 | 6138 |
| 5 | 110143 |
| 6 | 1976437 |
| 7 | 35465724 |
| 8 | 636406596 |
| 9 | 11419853005 |
| 10 | 204920947495 |
| 11 | 3677157201906 |
| 12 | 65983908686814 |
| 13 | 1184033199160747 |
| 14 | 21246613676206633 |
| 15 | 381255012972558648 |
| 16 | 6841343619829849032 |
| 17 | 122762930143964723929 |
| 18 | 2202891398971535181691 |