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 | 11 |
| 3 | 52 |
| 4 | 309 |
| 5 | 2221 |
| 6 | 18703 |
| 7 | 180216 |
| 8 | 1952457 |
| 9 | 23466223 |
| 10 | 309577971 |
| 11 | 4444537868 |
| 12 | 68948023741 |
| 13 | 1148825560377 |
| 14 | 20455144724407 |
| 15 | 387479309532976 |
| 16 | 7778881684953873 |
| 17 | 164942847995071611 |
| 18 | 3682885668837002587 |
| 19 | 86359724102207331876 |
| 20 | 2121535102985378053061 |
| 21 | 54482075844410029721893 |
| 22 | 1459677302947807284662751 |