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 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 8 |
| 6 | 43 |
| 7 | 398 |
| 8 | 6413 |
| 9 | 184596 |
| 10 | 9540998 |
| 11 | 894012628 |
| 12 | 153204356304 |
| 13 | 48387996396590 |
| 14 | 28352880689501075 |
| 15 | 30992600581556641380 |
| 16 | 63499394791445838416399 |
| 17 | 244849247994227524521679624 |
| 18 | 1783153933475289754036309451798 |
| 19 | 24603857772350530383609071261316942 |