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 | 63 |
| 2 | 364 |
| 3 | 3906 |
| 4 | 19608 |
| 5 | 177156 |
| 6 | 402234 |
| 7 | 1508598 |
| 8 | 2613660 |
| 9 | 6728904 |
| 10 | 21243690 |
| 11 | 29583456 |
| 12 | 71270178 |
| 13 | 118752606 |
| 14 | 150508644 |
| 15 | 234330768 |
| 16 | 426237714 |
| 17 | 727250580 |
| 18 | 858672906 |
| 19 | 1370581548 |
| 20 | 1830004056 |
| 21 | 2101864254 |
| 22 | 3116505840 |
| 23 | 3987077724 |