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 | 5 |
| 3 | 23 |
| 4 | 106 |
| 5 | 496 |
| 6 | 2361 |
| 7 | 11425 |
| 8 | 56128 |
| 9 | 279530 |
| 10 | 1409242 |
| 11 | 7182570 |
| 12 | 36965292 |
| 13 | 191896092 |
| 14 | 1003889999 |
| 15 | 5288020783 |
| 16 | 28026601758 |
| 17 | 149362212188 |
| 18 | 799947847992 |
| 19 | 4303496405324 |
| 20 | 23245282077346 |
| 21 | 126020035603358 |
| 22 | 685477891161324 |