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 | 2 |
| 3 | 2 |
| 4 | 7 |
| 5 | 14 |
| 6 | 37 |
| 7 | 90 |
| 8 | 233 |
| 9 | 602 |
| 10 | 1586 |
| 11 | 4212 |
| 12 | 11299 |
| 13 | 30536 |
| 14 | 83098 |
| 15 | 227474 |
| 16 | 625993 |
| 17 | 1730786 |
| 18 | 4805596 |
| 19 | 13393688 |
| 20 | 37458331 |
| 21 | 105089228 |
| 22 | 295673995 |
| 23 | 834086420 |
| 24 | 2358641377 |
| 25 | 6684761124 |
| 26 | 18985057352 |
| 27 | 54022715450 |
| 28 | 154000562759 |
| 29 | 439742222070 |
| 30 | 1257643249141 |