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 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 80 |
| 5 | 232 |
| 6 | 656 |
| 7 | 1808 |
| 8 | 4864 |
| 9 | 12800 |
| 10 | 33024 |
| 11 | 83712 |
| 12 | 208896 |
| 13 | 514048 |
| 14 | 1249280 |
| 15 | 3002368 |
| 16 | 7143424 |
| 17 | 16842752 |
| 18 | 39387136 |
| 19 | 91422720 |
| 20 | 210763776 |
| 21 | 482869248 |
| 22 | 1099956224 |
| 23 | 2492465152 |
| 24 | 5620367360 |
| 25 | 12616466432 |
| 26 | 28202500096 |
| 27 | 62797119488 |
| 28 | 139318001664 |
| 29 | 308029685760 |