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 | 12 |
| 3 | 198 |
| 4 | 3604 |
| 5 | 69405 |
| 6 | 1386048 |
| 7 | 28403620 |
| 8 | 593399416 |
| 9 | 12584663901 |
| 10 | 270123960220 |
| 11 | 5855607723702 |
| 12 | 127986261470436 |
| 13 | 2817048848634449 |
| 14 | 62378907950601228 |
| 15 | 1388516401122627270 |