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 | 2 |
| 1 | 6 |
| 2 | 18 |
| 3 | 30 |
| 4 | 90 |
| 5 | 270 |
| 6 | 450 |
| 7 | 210 |
| 8 | 630 |
| 9 | 6750 |
| 10 | 20250 |
| 11 | 9450 |
| 12 | 15750 |
| 13 | 47250 |
| 14 | 22050 |
| 15 | 2310 |
| 16 | 6930 |
| 17 | 330750 |
| 18 | 3543750 |
| 19 | 1653750 |
| 20 | 4961250 |
| 21 | 53156250 |
| 22 | 24806250 |
| 23 | 727650 |
| 24 | 1212750 |
| 25 | 57881250 |
| 26 | 173643750 |
| 27 | 18191250 |
| 28 | 8489250 |
| 29 | 25467750 |
| 30 | 2668050 |
| 31 | 30030 |
| 32 | 90090 |
| 33 | 40020750 |
| 34 | 1910081250 |
| 35 | 891371250 |
| 36 | 9550406250 |
| 37 | 455814843750 |
| 38 | 212713593750 |