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 | 5 |
| 2 | 19 |
| 3 | 57 |
| 4 | 127 |
| 5 | 293 |
| 6 | 663 |
| 7 | 1517 |
| 8 | 3459 |
| 9 | 7905 |
| 10 | 18051 |
| 11 | 41239 |
| 12 | 94203 |
| 13 | 215217 |
| 14 | 491661 |
| 15 | 1123219 |
| 16 | 2566023 |
| 17 | 5862189 |
| 18 | 13392389 |
| 19 | 30595439 |
| 20 | 69896451 |
| 21 | 159681185 |
| 22 | 364797903 |
| 23 | 833395099 |
| 24 | 1903923685 |
| 25 | 4349588175 |
| 26 | 9936804401 |
| 27 | 22701018621 |
| 28 | 51861365563 |