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 | 3 |
| 1 | 16 |
| 2 | 73 |
| 3 | 316 |
| 4 | 1334 |
| 5 | 5552 |
| 6 | 22901 |
| 7 | 93892 |
| 8 | 383290 |
| 9 | 1559680 |
| 10 | 6331098 |
| 11 | 25649976 |
| 12 | 103758828 |
| 13 | 419195552 |
| 14 | 1691825933 |
| 15 | 6822051092 |
| 16 | 27488564498 |
| 17 | 110691186272 |
| 18 | 445487285678 |
| 19 | 1792047789512 |
| 20 | 7205785665908 |
| 21 | 28963557761312 |