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 | 7 |
| 3 | 15 |
| 4 | 31 |
| 5 | 63 |
| 6 | 131 |
| 7 | 279 |
| 8 | 621 |
| 9 | 1469 |
| 10 | 3766 |
| 11 | 10694 |
| 12 | 34728 |
| 13 | 133582 |
| 14 | 636719 |
| 15 | 3955451 |
| 16 | 33664265 |
| 17 | 407703531 |
| 18 | 7147333784 |
| 19 | 180948983492 |
| 20 | 6537204164708 |
| 21 | 332740721681412 |
| 22 | 23627093701822296 |
| 23 | 2324803141466748032 |
| 24 | 315610211340647518667 |
| 25 | 58953876234603150481383 |