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 | 19 |
| 3 | 204 |
| 4 | 1956 |
| 5 | 18245 |
| 6 | 168497 |
| 7 | 1555811 |
| 8 | 14426124 |
| 9 | 134432669 |
| 10 | 1258822220 |
| 11 | 11840335764 |
| 12 | 111817881036 |
| 13 | 1059796387004 |
| 14 | 10076978543513 |
| 15 | 96091983644261 |
| 16 | 918679875630905 |
| 17 | 8803388145953381 |
| 18 | 84537081118605467 |
| 19 | 813340036541900706 |
| 20 | 7838825925851034479 |
| 21 | 75669246175972479567 |