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 | 4 |
| 1 | 16 |
| 2 | 88 |
| 3 | 538 |
| 4 | 3568 |
| 5 | 24596 |
| 6 | 176354 |
| 7 | 1298732 |
| 8 | 9788838 |
| 9 | 75190990 |
| 10 | 586994548 |
| 11 | 4646450800 |
| 12 | 37225608048 |
| 13 | 301400446752 |
| 14 | 2463161448024 |
| 15 | 20297411421166 |
| 16 | 168503717726980 |
| 17 | 1408243135178256 |
| 18 | 11840473621942108 |
| 19 | 100102553809842544 |