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 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 8 |
| 8 | 18 |
| 9 | 45 |
| 10 | 122 |
| 11 | 350 |
| 12 | 1052 |
| 13 | 3313 |
| 14 | 10933 |
| 15 | 37739 |
| 16 | 135865 |
| 17 | 508545 |
| 18 | 1973717 |
| 19 | 7926795 |
| 20 | 32895354 |
| 21 | 140894024 |
| 22 | 622160220 |
| 23 | 2829323210 |
| 24 | 13235526027 |
| 25 | 63620528705 |
| 26 | 313909404040 |
| 27 | 1588405927920 |
| 28 | 8235905545581 |
| 29 | 43724990832997 |
| 30 | 237527663672208 |
| 31 | 1319398402129845 |