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 | 10 |
| 3 | 30 |
| 4 | 90 |
| 5 | 294 |
| 6 | 964 |
| 7 | 3304 |
| 8 | 11464 |
| 9 | 40584 |
| 10 | 145338 |
| 11 | 526638 |
| 12 | 1924378 |
| 13 | 7086598 |
| 14 | 26259388 |
| 15 | 97842104 |
| 16 | 366273464 |
| 17 | 1376854004 |
| 18 | 5194587924 |
| 19 | 19661846184 |
| 20 | 74637375132 |
| 21 | 284068160592 |
| 22 | 1083712790142 |
| 23 | 4143223406562 |
| 24 | 15871346734402 |
| 25 | 60907343008066 |
| 26 | 234122710710436 |