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 | 1 |
| 2 | 6 |
| 3 | 21 |
| 4 | 68 |
| 5 | 205 |
| 6 | 594 |
| 7 | 1673 |
| 8 | 4616 |
| 9 | 12537 |
| 10 | 33630 |
| 11 | 89309 |
| 12 | 235212 |
| 13 | 615173 |
| 14 | 1599402 |
| 15 | 4137105 |
| 16 | 10653712 |
| 17 | 27327857 |
| 18 | 69856182 |
| 19 | 178017061 |
| 20 | 452390740 |
| 21 | 1146776253 |
| 22 | 2900399106 |
| 23 | 7320463897 |
| 24 | 18441561624 |
| 25 | 46376946025 |
| 26 | 116442406158 |
| 27 | 291929022189 |
| 28 | 730881930716 |
| 29 | 1827523107829 |