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 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 18 |
| 6 | 30 |
| 7 | 90 |
| 8 | 270 |
| 9 | 450 |
| 10 | 630 |
| 11 | 6750 |
| 12 | 20250 |
| 13 | 47250 |
| 14 | 330750 |
| 15 | 3543750 |
| 16 | 4961250 |
| 17 | 53156250 |
| 18 | 57881250 |
| 19 | 173643750 |
| 20 | 1910081250 |
| 21 | 9550406250 |
| 22 | 455814843750 |
| 23 | 3190703906250 |
| 24 | 34186113281250 |
| 25 | 245684200781250 |
| 26 | 29727788294531250 |
| 27 | 3310594605527343750 |
| 28 | 158005651627441406250 |
| 29 | 1738062167901855468750 |
| 30 | 414764835522033691406250 |