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 | 1 |
| 2 | 3 |
| 3 | 5 |
| 4 | 21 |
| 5 | 69 |
| 6 | 319 |
| 7 | 1957 |
| 8 | 12513 |
| 9 | 85445 |
| 10 | 656771 |
| 11 | 5591277 |
| 12 | 51531405 |
| 13 | 509874417 |
| 14 | 5438826975 |
| 15 | 62000480093 |
| 16 | 752464463029 |
| 17 | 9685138399785 |
| 18 | 131777883431119 |