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) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 22 |
| 4 | 111 |
| 5 | 486 |
| 6 | 3772 |
| 7 | 29142 |
| 8 | 275871 |
| 9 | 2830459 |
| 10 | 32028882 |
| 11 | 392744078 |
| 12 | 5201524044 |
| 13 | 73943424582 |
| 14 | 1123603726896 |
| 15 | 18176728661832 |
| 16 | 311951284854975 |
| 17 | 5661698774848910 |
| 18 | 108355867352001811 |
| 19 | 2181096921557783966 |
| 20 | 46066653293892718506 |
| 21 | 1018705098450761473704 |