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 | 0 |
| 1 | 1 |
| 2 | 11 |
| 3 | 92 |
| 4 | 693 |
| 5 | 4955 |
| 6 | 34408 |
| 7 | 234793 |
| 8 | 1584891 |
| 9 | 10624804 |
| 10 | 70911005 |
| 11 | 471901739 |
| 12 | 3134499984 |
| 13 | 20794349393 |
| 14 | 137837343787 |
| 15 | 913174649260 |
| 16 | 6047638172037 |
| 17 | 40041955063867 |
| 18 | 265079998713464 |
| 19 | 1754663288995961 |
| 20 | 11613976216265115 |