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 | 100 |
| 4 | 593 |
| 5 | 3497 |
| 6 | 20316 |
| 7 | 116378 |
| 8 | 658214 |
| 9 | 3679450 |
| 10 | 20350028 |
| 11 | 111459648 |
| 12 | 605060633 |
| 13 | 3257784589 |
| 14 | 17408647968 |
| 15 | 92378535290 |
| 16 | 487031130699 |
| 17 | 2552197485757 |
| 18 | 13298890952222 |
| 19 | 68930923717598 |
| 20 | 355507581655752 |
| 21 | 1824924721216084 |
| 22 | 9326440815314046 |
| 23 | 47464093855706540 |