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 | 2 |
| 2 | 8 |
| 3 | 28 |
| 4 | 116 |
| 5 | 468 |
| 6 | 2004 |
| 7 | 8580 |
| 8 | 37700 |
| 9 | 166612 |
| 10 | 746420 |
| 11 | 3364964 |
| 12 | 15297508 |
| 13 | 69924788 |
| 14 | 321492948 |
| 15 | 1484809668 |
| 16 | 6887663748 |
| 17 | 32068609428 |
| 18 | 149827726068 |
| 19 | 702154578468 |
| 20 | 3299912205348 |
| 21 | 15548337659508 |
| 22 | 73433355989268 |
| 23 | 347572725355908 |