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 | 1 |
| 1 | 6 |
| 2 | 45 |
| 3 | 411 |
| 4 | 4449 |
| 5 | 55803 |
| 6 | 796581 |
| 7 | 12757503 |
| 8 | 226588257 |
| 9 | 4420898595 |
| 10 | 94001021589 |
| 11 | 2163619250895 |
| 12 | 53598352999905 |
| 13 | 1421924243354787 |
| 14 | 40221778417553637 |
| 15 | 1208471542554184767 |
| 16 | 38434396264371831873 |
| 17 | 1289995362325669726659 |
| 18 | 45567027291743788320405 |