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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 3 |
| 5 | 3 |
| 6 | 9 |
| 7 | 63 |
| 8 | 63 |
| 9 | 567 |
| 10 | 567 |
| 11 | 6237 |
| 12 | 18711 |
| 13 | 243243 |
| 14 | 1702701 |
| 15 | 5108103 |
| 16 | 5108103 |
| 17 | 86837751 |
| 18 | 781539759 |
| 19 | 14849255421 |
| 20 | 14849255421 |
| 21 | 311834363841 |
| 22 | 3430178002251 |
| 23 | 78894094051773 |
| 24 | 236682282155319 |
| 25 | 236682282155319 |
| 26 | 3076869668019147 |
| 27 | 83075481036516969 |