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 | 104 |
| 5 | 614 |
| 6 | 3816 |
| 7 | 24595 |
| 8 | 162896 |
| 9 | 1101922 |
| 10 | 7580904 |
| 11 | 52878654 |
| 12 | 373100272 |
| 13 | 2658188524 |
| 14 | 19096607120 |
| 15 | 138182654595 |
| 16 | 1006202473888 |
| 17 | 7367648586954 |
| 18 | 54214472633064 |
| 19 | 400698865376842 |
| 20 | 2973344993337520 |
| 21 | 22142778865313364 |