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 | 1 |
| 2 | 4 |
| 3 | 15 |
| 4 | 62 |
| 5 | 262 |
| 6 | 1148 |
| 7 | 5123 |
| 8 | 23316 |
| 9 | 107570 |
| 10 | 502664 |
| 11 | 2372786 |
| 12 | 11302858 |
| 13 | 54256236 |
| 14 | 262226900 |
| 15 | 1274944859 |
| 16 | 6231845040 |
| 17 | 30605344282 |
| 18 | 150948390672 |
| 19 | 747356368322 |
| 20 | 3713140528364 |
| 21 | 18506907541124 |
| 22 | 92509837573736 |
| 23 | 463660345091686 |