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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 31 |
| 6 | 91 |
| 7 | 259 |
| 8 | 726 |
| 9 | 2007 |
| 10 | 5489 |
| 11 | 14888 |
| 12 | 40122 |
| 13 | 107574 |
| 14 | 287239 |
| 15 | 764405 |
| 16 | 2028679 |
| 17 | 5371858 |
| 18 | 14198008 |
| 19 | 37467982 |
| 20 | 98749767 |
| 21 | 259984452 |
| 22 | 683865318 |
| 23 | 1797500121 |
| 24 | 4721662597 |
| 25 | 12396308875 |
| 26 | 32531025970 |
| 27 | 85337831350 |
| 28 | 223794544179 |
| 29 | 586736215856 |
| 30 | 1537941527011 |