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 | 10 |
| 4 | 47 |
| 5 | 201 |
| 6 | 849 |
| 7 | 3578 |
| 8 | 15147 |
| 9 | 64516 |
| 10 | 276268 |
| 11 | 1188342 |
| 12 | 5130987 |
| 13 | 22226036 |
| 14 | 96543989 |
| 15 | 420368843 |
| 16 | 1834203939 |
| 17 | 8018057328 |
| 18 | 35107961157 |
| 19 | 153950675566 |
| 20 | 675978772306 |
| 21 | 2971700764920 |
| 22 | 13078268135661 |
| 23 | 57613905606250 |
| 24 | 254038914924767 |
| 25 | 1121081799217206 |
| 26 | 4951199308679965 |