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 | 13 |
| 2 | 97 |
| 3 | 685 |
| 4 | 4801 |
| 5 | 33613 |
| 6 | 235297 |
| 7 | 1647085 |
| 8 | 11529601 |
| 9 | 80707213 |
| 10 | 564950497 |
| 11 | 3954653485 |
| 12 | 27682574401 |
| 13 | 193778020813 |
| 14 | 1356446145697 |
| 15 | 9495123019885 |
| 16 | 66465861139201 |
| 17 | 465261027974413 |
| 18 | 3256827195820897 |
| 19 | 22797790370746285 |