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) |
|---|---|
| 2 | 1 |
| 3 | 7 |
| 4 | 38 |
| 5 | 201 |
| 6 | 991 |
| 7 | 5119 |
| 8 | 25108 |
| 9 | 131207 |
| 10 | 652171 |
| 11 | 3467959 |
| 12 | 17536482 |
| 13 | 94772169 |
| 14 | 487259131 |
| 15 | 2668269045 |
| 16 | 13920305080 |
| 17 | 77008669339 |
| 18 | 406737748473 |
| 19 | 2267418205201 |
| 20 | 12099265896022 |
| 21 | 67836037484417 |
| 22 | 365071772684071 |
| 23 | 2055622507395167 |
| 24 | 11141223793940397 |
| 25 | 62938095325080771 |