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) |
|---|---|
| 3 | 4 |
| 4 | 17 |
| 5 | 66 |
| 6 | 221 |
| 7 | 688 |
| 8 | 2034 |
| 9 | 5788 |
| 10 | 15998 |
| 11 | 43192 |
| 12 | 114496 |
| 13 | 298712 |
| 14 | 769340 |
| 15 | 1959064 |
| 16 | 4940761 |
| 17 | 12354210 |
| 18 | 30660947 |
| 19 | 75583868 |
| 20 | 185208833 |
| 21 | 451356846 |
| 22 | 1094522547 |
| 23 | 2642121008 |
| 24 | 6351335083 |
| 25 | 15208854510 |
| 26 | 36288478177 |
| 27 | 86295204732 |
| 28 | 204571273167 |
| 29 | 483532711338 |
| 30 | 1139738858221 |