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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 21 |
| 5 | 61 |
| 6 | 193 |
| 7 | 617 |
| 8 | 2047 |
| 9 | 6895 |
| 10 | 23691 |
| 11 | 82435 |
| 12 | 290447 |
| 13 | 1033215 |
| 14 | 3707655 |
| 15 | 13402071 |
| 16 | 48759741 |
| 17 | 178403101 |
| 18 | 656041801 |
| 19 | 2423300129 |
| 20 | 8987420549 |
| 21 | 33453670773 |
| 22 | 124936234413 |
| 23 | 467995789277 |
| 24 | 1757899936601 |