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 | 4 |
| 2 | 34 |
| 3 | 247 |
| 4 | 1712 |
| 5 | 11185 |
| 6 | 68963 |
| 7 | 409849 |
| 8 | 2367507 |
| 9 | 13377156 |
| 10 | 74342563 |
| 11 | 407818620 |
| 12 | 2214357712 |
| 13 | 11926066887 |
| 14 | 63809981451 |
| 15 | 339576381990 |
| 16 | 1799025041767 |
| 17 | 9494920297227 |
| 18 | 49950199374227 |
| 19 | 262036734664892 |