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 | 0 |
| 2 | 2 |
| 3 | 16 |
| 4 | 119 |
| 5 | 924 |
| 6 | 7445 |
| 7 | 63129 |
| 8 | 547572 |
| 9 | 4838319 |
| 10 | 4814936 |
| 11 | 43167234 |
| 12 | 391378851 |
| 13 | 3580266494 |
| 14 | 32997926272 |
| 15 | 306051434210 |
| 16 | 2853931339135 |
| 17 | 26737370196938 |
| 18 | 251515351394258 |
| 19 | 2374493400086829 |
| 20 | 22488661383368556 |
| 21 | 213597279448646179 |
| 22 | 2033961812788210675 |
| 23 | 19413250431142245897 |