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 | 12 |
| 2 | 28 |
| 3 | 56 |
| 4 | 116 |
| 5 | 236 |
| 6 | 476 |
| 7 | 952 |
| 8 | 1908 |
| 9 | 3820 |
| 10 | 7644 |
| 11 | 15288 |
| 12 | 30580 |
| 13 | 61164 |
| 14 | 122332 |
| 15 | 244664 |
| 16 | 489332 |
| 17 | 978668 |
| 18 | 1957340 |
| 19 | 3914680 |
| 20 | 7829364 |
| 21 | 15658732 |
| 22 | 31317468 |
| 23 | 62634936 |
| 24 | 125269876 |
| 25 | 250539756 |
| 26 | 501079516 |
| 27 | 1002159032 |
| 28 | 2004318068 |