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) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 338 |
| 4 | 2287 |
| 5 | 15186 |
| 6 | 99344 |
| 7 | 644040 |
| 8 | 4164930 |
| 9 | 26882466 |
| 10 | 173276640 |
| 11 | 1115910270 |
| 12 | 7182799173 |
| 13 | 46220503936 |
| 14 | 297376327082 |
| 15 | 1913081363032 |
| 16 | 12306454081360 |
| 17 | 79161863609011 |
| 18 | 509201240096045 |
| 19 | 3275346169991511 |
| 20 | 21067913854706817 |