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 | 0 |
| 1 | 1 |
| 2 | 13 |
| 3 | 199 |
| 4 | 2977 |
| 5 | 44671 |
| 6 | 670033 |
| 7 | 10050559 |
| 8 | 150758257 |
| 9 | 2261374111 |
| 10 | 33920611153 |
| 11 | 508809168319 |
| 12 | 7632137522737 |
| 13 | 114482062845151 |
| 14 | 1717230942669073 |
| 15 | 25758464140052479 |
| 16 | 386376962100754417 |
| 17 | 5795654431511381791 |
| 18 | 86934816472670595793 |
| 19 | 1304022247090059199039 |