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 | 1 |
| 2 | 4 |
| 3 | 19 |
| 4 | 92 |
| 5 | 421 |
| 6 | 1830 |
| 7 | 7687 |
| 8 | 31624 |
| 9 | 128521 |
| 10 | 518666 |
| 11 | 2084875 |
| 12 | 8361996 |
| 13 | 33497101 |
| 14 | 134094862 |
| 15 | 536608783 |
| 16 | 2146926608 |
| 17 | 8588754961 |
| 18 | 34357248018 |
| 19 | 137433710611 |
| 20 | 549744803860 |
| 21 | 2199000186901 |
| 22 | 8796044787734 |
| 23 | 35184271425559 |
| 24 | 140737278640152 |
| 25 | 562949517213721 |