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 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 79 |
| 6 | 474 |
| 7 | 3468 |
| 8 | 29799 |
| 9 | 293528 |
| 10 | 3258373 |
| 11 | 40234231 |
| 12 | 546921835 |
| 13 | 8115147998 |
| 14 | 130503876054 |
| 15 | 2260929219675 |
| 16 | 41979302557200 |
| 17 | 831593152814251 |
| 18 | 17506400133530765 |
| 19 | 390278100156698627 |
| 20 | 9185223726173708408 |
| 21 | 227578002295869672508 |
| 22 | 5921091852493279814589 |