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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 31 |
| 6 | 112 |
| 7 | 466 |
| 8 | 2124 |
| 9 | 10476 |
| 10 | 55058 |
| 11 | 301632 |
| 12 | 1703989 |
| 13 | 9819215 |
| 14 | 57364723 |
| 15 | 338134486 |
| 16 | 2005132504 |
| 17 | 11937364183 |
| 18 | 71254885362 |
| 19 | 426063226936 |
| 20 | 2550552259119 |
| 21 | 15280103806730 |
| 22 | 91588103894781 |