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) |
|---|---|
| 3 | 6 |
| 4 | 21 |
| 5 | 57 |
| 6 | 138 |
| 7 | 294 |
| 8 | 606 |
| 9 | 1170 |
| 10 | 2208 |
| 11 | 4008 |
| 12 | 7176 |
| 13 | 12492 |
| 14 | 21510 |
| 15 | 36348 |
| 16 | 60801 |
| 17 | 100281 |
| 18 | 164019 |
| 19 | 265263 |
| 20 | 425853 |