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 | 10 |
| 2 | 42 |
| 3 | 156 |
| 4 | 570 |
| 5 | 2096 |
| 6 | 7784 |
| 7 | 29168 |
| 8 | 110106 |
| 9 | 418128 |
| 10 | 1595616 |
| 11 | 6113740 |
| 12 | 23505352 |
| 13 | 90633796 |
| 14 | 350351636 |
| 15 | 1357278296 |
| 16 | 5268292826 |
| 17 | 20483876816 |
| 18 | 79765662896 |
| 19 | 311038321436 |
| 20 | 1214362277696 |
| 21 | 4746455801876 |
| 22 | 18570960418916 |