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 | 10 |
| 4 | 118 |
| 5 | 818 |
| 6 | 5092 |
| 7 | 27564 |
| 8 | 137836 |
| 9 | 644836 |
| 10 | 2870189 |
| 11 | 12266918 |
| 12 | 50724954 |
| 13 | 204046142 |
| 14 | 801892081 |
| 15 | 3089123960 |
| 16 | 11696423536 |
| 17 | 43623049688 |
| 18 | 160547844283 |
| 19 | 583940294930 |
| 20 | 2101624362838 |
| 21 | 7492542382034 |
| 22 | 26484322064854 |
| 23 | 92891831844644 |
| 24 | 323514376584988 |
| 25 | 1119432296516028 |
| 26 | 3850521166068067 |