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 | 15 |
| 1 | 21 |
| 2 | 35 |
| 3 | 69 |
| 4 | 155 |
| 5 | 381 |
| 6 | 995 |
| 7 | 2709 |
| 8 | 7595 |
| 9 | 21741 |
| 10 | 63155 |
| 11 | 185349 |
| 12 | 547835 |
| 13 | 1627101 |
| 14 | 4848515 |
| 15 | 14479989 |
| 16 | 43308875 |
| 17 | 129664461 |
| 18 | 388469075 |
| 19 | 1164358629 |
| 20 | 3490978715 |
| 21 | 10468741821 |
| 22 | 31397836835 |
| 23 | 94176733269 |
| 24 | 282496645355 |
| 25 | 847422827181 |
| 26 | 2542134263795 |
| 27 | 7626134355909 |