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 | 39 |
| 5 | 127 |
| 6 | 480 |
| 7 | 2143 |
| 8 | 10907 |
| 9 | 62495 |
| 10 | 397814 |
| 11 | 2785861 |
| 12 | 21282228 |
| 13 | 176133285 |
| 14 | 1569817724 |
| 15 | 14990658724 |
| 16 | 152693582275 |
| 17 | 1652531857935 |
| 18 | 18936620009722 |
| 19 | 229053108410969 |
| 20 | 2916394751599614 |
| 21 | 38989325834726043 |
| 22 | 546070266163669664 |
| 23 | 7995699956778626764 |