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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 43 |
| 6 | 217 |
| 7 | 3913 |
| 8 | 9133 |
| 9 | 73067 |
| 10 | 1972819 |
| 11 | 6576067 |
| 12 | 24112247 |
| 13 | 372017527 |
| 14 | 1612075951 |
| 15 | 157983443203 |
| 16 | 7109254944151 |
| 17 | 37916026368811 |
| 18 | 644572448269793 |
| 19 | 34806912206568841 |
| 20 | 2422459091299663 |
| 21 | 7775794614048301 |
| 22 | 277759159408419360043 |
| 23 | 2036900502328408640323 |
| 24 | 46848711553553398727437 |