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 | 1 |
| 1 | 4 |
| 2 | 16 |
| 3 | 53 |
| 4 | 166 |
| 5 | 492 |
| 6 | 1413 |
| 7 | 3960 |
| 8 | 10912 |
| 9 | 29689 |
| 10 | 80026 |
| 11 | 214196 |
| 12 | 570289 |
| 13 | 1512300 |
| 14 | 3998160 |
| 15 | 10545741 |
| 16 | 27766942 |
| 17 | 73012060 |
| 18 | 191785165 |
| 19 | 503378480 |
| 20 | 1320425536 |
| 21 | 3462057009 |
| 22 | 9074076786 |
| 23 | 23776857828 |
| 24 | 62289901081 |
| 25 | 163159711492 |