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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 2 |
| 7 | 140 |
| 8 | 3262 |
| 9 | 47802 |
| 10 | 535990 |
| 11 | 5038418 |
| 12 | 41781432 |
| 13 | 315447990 |
| 14 | 2214289350 |
| 15 | 14664659100 |
| 16 | 92612930280 |
| 17 | 562220244768 |
| 18 | 3301016862024 |
| 19 | 18836205435208 |
| 20 | 104862661271840 |
| 21 | 571336322754792 |
| 22 | 3054404571541092 |
| 23 | 16056744308319000 |