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 | 9 |
| 2 | 28 |
| 3 | 57 |
| 4 | 115 |
| 5 | 231 |
| 6 | 694 |
| 7 | 1389 |
| 8 | 2779 |
| 9 | 5559 |
| 10 | 16678 |
| 11 | 33357 |
| 12 | 66715 |
| 13 | 133431 |
| 14 | 400294 |
| 15 | 800589 |
| 16 | 1601179 |
| 17 | 3202359 |
| 18 | 9607078 |
| 19 | 19214157 |
| 20 | 38428315 |
| 21 | 76856631 |
| 22 | 153713263 |
| 23 | 307426527 |
| 24 | 614853055 |
| 25 | 1229706111 |
| 26 | 3689118334 |
| 27 | 7378236669 |
| 28 | 14756473339 |