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 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 18 |
| 6 | 58 |
| 7 | 221 |
| 8 | 1055 |
| 9 | 6485 |
| 10 | 50536 |
| 11 | 478836 |
| 12 | 5440177 |
| 13 | 76190368 |
| 14 | 1363369202 |
| 15 | 31071197441 |
| 16 | 868697997215 |
| 17 | 29108097152159 |
| 18 | 1188937117381254 |
| 19 | 61492149340335133 |
| 20 | 4073478163425582443 |
| 21 | 335184988593624746984 |
| 22 | 33170032360612393972748 |