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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 13 |
| 6 | 35 |
| 7 | 83 |
| 8 | 217 |
| 9 | 556 |
| 10 | 1504 |
| 11 | 4103 |
| 12 | 11715 |
| 13 | 34137 |
| 14 | 103155 |
| 15 | 320217 |
| 16 | 1025757 |
| 17 | 3376889 |
| 18 | 11436712 |
| 19 | 39758152 |
| 20 | 141817521 |
| 21 | 518322115 |
| 22 | 1939518461 |
| 23 | 7422543892 |
| 24 | 29028055198 |
| 25 | 115908161428 |
| 26 | 472185530376 |
| 27 | 1961087909565 |
| 28 | 8298093611774 |
| 29 | 35750704171225 |
| 30 | 156734314212418 |