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 | 16 |
| 3 | 50 |
| 4 | 154 |
| 5 | 470 |
| 6 | 1426 |
| 7 | 4310 |
| 8 | 12994 |
| 9 | 39110 |
| 10 | 117586 |
| 11 | 353270 |
| 12 | 1060834 |
| 13 | 3184550 |
| 14 | 9557746 |
| 15 | 28681430 |
| 16 | 86060674 |
| 17 | 258214790 |
| 18 | 774709906 |
| 19 | 2324260790 |
| 20 | 6973044514 |
| 21 | 20919657830 |
| 22 | 62760022066 |
| 23 | 188282163350 |
| 24 | 564850684354 |
| 25 | 1694560441670 |
| 26 | 5083698102226 |
| 27 | 15251127861110 |
| 28 | 45753450692194 |
| 29 | 137260486294310 |
| 30 | 411781727318386 |