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 | 8 |
| 3 | 37 |
| 4 | 192 |
| 5 | 899 |
| 6 | 3880 |
| 7 | 16041 |
| 8 | 65024 |
| 9 | 261415 |
| 10 | 1047576 |
| 11 | 4192973 |
| 12 | 16775488 |
| 13 | 67106667 |
| 14 | 268432712 |
| 15 | 1073738449 |
| 16 | 4294963200 |
| 17 | 17179864271 |
| 18 | 68719470904 |
| 19 | 274877900085 |
| 20 | 1099511619776 |
| 21 | 4398046501843 |
| 22 | 17592186033768 |
| 23 | 70368744165497 |
| 24 | 281474976696832 |