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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 12 |
| 4 | 98 |
| 5 | 684 |
| 6 | 4403 |
| 7 | 27048 |
| 8 | 161412 |
| 9 | 945288 |
| 10 | 5466549 |
| 11 | 31340628 |
| 12 | 178604998 |
| 13 | 1013573652 |
| 14 | 5735117479 |
| 15 | 32385232272 |
| 16 | 182622362504 |
| 17 | 1028897389008 |
| 18 | 5793703249449 |
| 19 | 32615362319580 |
| 20 | 183593293074730 |
| 21 | 1033535639454780 |
| 22 | 5819389057957211 |
| 23 | 32775522041862072 |
| 24 | 184658694508103180 |