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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 4 |
| 6 | 12 |
| 7 | 19 |
| 8 | 51 |
| 9 | 106 |
| 10 | 274 |
| 11 | 647 |
| 12 | 1773 |
| 13 | 4664 |
| 14 | 13418 |
| 15 | 38861 |
| 16 | 118690 |
| 17 | 370588 |
| 18 | 1202924 |
| 19 | 4006557 |
| 20 | 13764760 |
| 21 | 48517672 |
| 22 | 175603676 |
| 23 | 651026060 |
| 24 | 2471150365 |
| 25 | 9590103580 |
| 26 | 38023295735 |
| 27 | 153871104726 |
| 28 | 635078474978 |
| 29 | 2671365285303 |
| 30 | 11444367926725 |
| 31 | 49903627379427 |