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 | 4 |
| 2 | 16 |
| 3 | 72 |
| 4 | 142 |
| 5 | 332 |
| 6 | 668 |
| 7 | 1356 |
| 8 | 2634 |
| 9 | 5046 |
| 10 | 9480 |
| 11 | 17594 |
| 12 | 32286 |
| 13 | 58730 |
| 14 | 106028 |
| 15 | 190204 |
| 16 | 339322 |
| 17 | 602416 |
| 18 | 1064888 |
| 19 | 1875104 |
| 20 | 3290166 |
| 21 | 5754586 |
| 22 | 10035236 |
| 23 | 17452462 |
| 24 | 30275242 |
| 25 | 52395822 |