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) |
|---|---|
| 1 | 1 |
| 2 | 11 |
| 3 | 80 |
| 4 | 609 |
| 5 | 4783 |
| 6 | 39175 |
| 7 | 332180 |
| 8 | 2880504 |
| 9 | 25423491 |
| 10 | 227523275 |
| 11 | 2059020280 |
| 12 | 18803924340 |
| 13 | 173032709183 |
| 14 | 1602470783672 |
| 15 | 14922284735484 |
| 16 | 139619168787795 |
| 17 | 1311778575685086 |
| 18 | 12369977142579584 |
| 19 | 117028833597800689 |
| 20 | 1110409801150582707 |