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 | 18 |
| 2 | 135 |
| 3 | 660 |
| 4 | 2475 |
| 5 | 7722 |
| 6 | 21021 |
| 7 | 51480 |
| 8 | 115830 |
| 9 | 243100 |
| 10 | 481338 |
| 11 | 906984 |
| 12 | 1637610 |
| 13 | 2848860 |
| 14 | 4796550 |
| 15 | 7845024 |
| 16 | 12503007 |
| 17 | 19468350 |
| 18 | 29683225 |
| 19 | 44401500 |
| 20 | 65270205 |
| 21 | 94427190 |
| 22 | 134617275 |
| 23 | 189329400 |
| 24 | 262957500 |
| 25 | 360988056 |
| 26 | 490217508 |
| 27 | 659002960 |
| 28 | 877549860 |
| 29 | 1158240600 |