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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 44 |
| 7 | 191 |
| 8 | 1229 |
| 9 | 13588 |
| 10 | 288597 |
| 11 | 12297299 |
| 12 | 1031342116 |
| 13 | 166123498733 |
| 14 | 50668194387427 |
| 15 | 29104827043066808 |
| 16 | 31455591302381718651 |
| 17 | 64032471448906164191208 |
| 18 | 245999896712611657677614268 |
| 19 | 1787823725136869060356731751124 |