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 | 28 |
| 4 | 86 |
| 5 | 265 |
| 6 | 816 |
| 7 | 2513 |
| 8 | 7739 |
| 9 | 23833 |
| 10 | 73396 |
| 11 | 226030 |
| 12 | 696081 |
| 13 | 2143648 |
| 14 | 6601569 |
| 15 | 20330163 |
| 16 | 62608681 |
| 17 | 192809420 |
| 18 | 593775046 |
| 19 | 1828587033 |
| 20 | 5631308624 |
| 21 | 17342153393 |
| 22 | 53406819691 |
| 23 | 164471408185 |
| 24 | 506505428836 |
| 25 | 1559831901918 |