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 | 9 |
| 3 | 89 |
| 4 | 873 |
| 5 | 8569 |
| 6 | 84105 |
| 7 | 825497 |
| 8 | 8102313 |
| 9 | 79524793 |
| 10 | 780541641 |
| 11 | 7661073113 |
| 12 | 75193991145 |
| 13 | 738034505209 |
| 14 | 7243862476041 |
| 15 | 71099038326041 |
| 16 | 697842244742697 |
| 17 | 6849372509292601 |
| 18 | 67227090541574985 |
| 19 | 659838794948515673 |
| 20 | 6476365878869240937 |
| 21 | 63566003269411293817 |