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 | 0 |
| 2 | 6 |
| 3 | 0 |
| 4 | 14 |
| 5 | 0 |
| 6 | 36 |
| 7 | 0 |
| 8 | 94 |
| 9 | 0 |
| 10 | 246 |
| 11 | 0 |
| 12 | 644 |
| 13 | 0 |
| 14 | 1686 |
| 15 | 0 |
| 16 | 4414 |
| 17 | 0 |
| 18 | 11556 |
| 19 | 0 |
| 20 | 30254 |
| 21 | 0 |
| 22 | 79206 |
| 23 | 0 |
| 24 | 207364 |
| 25 | 0 |
| 26 | 542886 |
| 27 | 0 |
| 28 | 1421294 |
| 29 | 0 |
| 30 | 3720996 |
| 31 | 0 |
| 32 | 9741694 |
| 33 | 0 |
| 34 | 25504086 |
| 35 | 0 |
| 36 | 66770564 |
| 37 | 0 |
| 38 | 174807606 |
| 39 | 0 |
| 40 | 457652254 |
| 41 | 0 |
| 42 | 1198149156 |
| 43 | 0 |
| 44 | 3136795214 |
| 45 | 0 |
| 46 | 8212236486 |
| 47 | 0 |
| 48 | 21499914244 |
| 49 | 0 |