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 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 31 |
| 6 | 120 |
| 7 | 511 |
| 8 | 2234 |
| 9 | 9988 |
| 10 | 45497 |
| 11 | 208435 |
| 12 | 959496 |
| 13 | 4414091 |
| 14 | 20252947 |
| 15 | 92586100 |
| 16 | 421351615 |
| 17 | 1910531192 |
| 18 | 8647504950 |
| 19 | 39194735661 |
| 20 | 178643040883 |
| 21 | 822295086652 |
| 22 | 3836023988259 |
| 23 | 18167435295220 |
| 24 | 87268076036356 |
| 25 | 423657019406289 |
| 26 | 2067868784722846 |