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 | 10 |
| 2 | 66 |
| 3 | 496 |
| 4 | 3556 |
| 5 | 26948 |
| 6 | 199898 |
| 7 | 1491120 |
| 8 | 11087686 |
| 9 | 82651544 |
| 10 | 615619076 |
| 11 | 4584511168 |
| 12 | 34147089394 |
| 13 | 254349422368 |
| 14 | 1894426012942 |
| 15 | 14110000555420 |
| 16 | 105095716711032 |
| 17 | 782780770095412 |
| 18 | 5830333131230406 |
| 19 | 43425808525532572 |
| 20 | 323446694496899910 |