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 | 22 |
| 2 | 142 |
| 3 | 730 |
| 4 | 4390 |
| 5 | 26742 |
| 6 | 166966 |
| 7 | 1056350 |
| 8 | 6755686 |
| 9 | 43557742 |
| 10 | 282683662 |
| 11 | 1844363158 |
| 12 | 12086792278 |
| 13 | 79504493454 |
| 14 | 524626264542 |
| 15 | 3471321731070 |
| 16 | 23023441009542 |
| 17 | 153019621221454 |
| 18 | 1018866986428048 |
| 19 | 6795005681508340 |