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 | 3 |
| 3 | 14 |
| 4 | 76 |
| 5 | 448 |
| 6 | 2791 |
| 7 | 18078 |
| 8 | 120516 |
| 9 | 821435 |
| 10 | 5698422 |
| 11 | 40101623 |
| 12 | 285583775 |
| 13 | 2054272430 |
| 14 | 14903954415 |
| 15 | 108932920861 |
| 16 | 801350333186 |
| 17 | 5928653489398 |
| 18 | 44084056075057 |
| 19 | 329279673851792 |
| 20 | 2469493161891742 |
| 21 | 18588339309502760 |
| 22 | 140383789476473354 |