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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 22 |
| 6 | 56 |
| 7 | 146 |
| 8 | 388 |
| 9 | 1048 |
| 10 | 2869 |
| 11 | 7942 |
| 12 | 22192 |
| 13 | 62510 |
| 14 | 177308 |
| 15 | 506008 |
| 16 | 1451866 |
| 17 | 4185788 |
| 18 | 12119696 |
| 19 | 35227748 |
| 20 | 102753800 |
| 21 | 300672368 |
| 22 | 882373261 |
| 23 | 2596389190 |
| 24 | 7658677856 |
| 25 | 22642421206 |
| 26 | 67081765932 |
| 27 | 199128719896 |
| 28 | 592179010350 |
| 29 | 1764044315540 |
| 30 | 5263275015120 |