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 | 3 |
| 2 | 16 |
| 3 | 95 |
| 4 | 591 |
| 5 | 3780 |
| 6 | 24620 |
| 7 | 162423 |
| 8 | 1081780 |
| 9 | 7258053 |
| 10 | 48982176 |
| 11 | 332140328 |
| 12 | 2261099491 |
| 13 | 15444137880 |
| 14 | 105789736896 |
| 15 | 726426836103 |
| 16 | 4998885106599 |
| 17 | 34464824536500 |
| 18 | 238017084356680 |
| 19 | 1646234203000485 |
| 20 | 11401464090042224 |
| 21 | 79060352485691272 |
| 22 | 548829398923188036 |