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 | 3 |
| 2 | 12 |
| 3 | 41 |
| 4 | 146 |
| 5 | 511 |
| 6 | 1798 |
| 7 | 6314 |
| 8 | 22187 |
| 9 | 77946 |
| 10 | 273856 |
| 11 | 962142 |
| 12 | 3380337 |
| 13 | 11876254 |
| 14 | 41725295 |
| 15 | 146595013 |
| 16 | 515037713 |
| 17 | 1809501081 |
| 18 | 6357387289 |
| 19 | 22335644540 |
| 20 | 78472648463 |
| 21 | 275700866485 |
| 22 | 968630080476 |
| 23 | 3403123989780 |