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 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 72 |
| 6 | 465 |
| 7 | 3362 |
| 8 | 26531 |
| 9 | 224856 |
| 10 | 2024188 |
| 11 | 19202830 |
| 12 | 190857879 |
| 13 | 1978567663 |
| 14 | 21319434418 |
| 15 | 238109360460 |
| 16 | 2750229390071 |
| 17 | 32789591062124 |
| 18 | 402891169846242 |
| 19 | 5094855923807780 |
| 20 | 66229610059651788 |
| 21 | 884081025776797026 |
| 22 | 12107164229698851942 |
| 23 | 169954380180177899277 |
| 24 | 2443554376412586234247 |