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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 21 |
| 6 | 56 |
| 7 | 149 |
| 8 | 404 |
| 9 | 1098 |
| 10 | 2982 |
| 11 | 8104 |
| 12 | 22027 |
| 13 | 59875 |
| 14 | 162756 |
| 15 | 442414 |
| 16 | 1202605 |
| 17 | 3269018 |
| 18 | 8886112 |
| 19 | 24154954 |
| 20 | 65659970 |
| 21 | 178482302 |
| 22 | 485165196 |
| 23 | 1318815735 |
| 24 | 3584912847 |
| 25 | 9744803447 |
| 26 | 26489122131 |
| 27 | 72004899338 |
| 28 | 195729609430 |