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) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 5 |
| 6 | 10 |
| 7 | 31 |
| 8 | 72 |
| 9 | 201 |
| 10 | 509 |
| 11 | 1374 |
| 12 | 3587 |
| 13 | 9647 |
| 14 | 25686 |
| 15 | 69348 |
| 16 | 187052 |
| 17 | 508480 |
| 18 | 1384959 |
| 19 | 3791466 |
| 20 | 10407842 |
| 21 | 28677319 |
| 22 | 79231664 |
| 23 | 219557624 |
| 24 | 609922977 |
| 25 | 1698526750 |
| 26 | 4740469708 |
| 27 | 13258136509 |
| 28 | 37151664771 |
| 29 | 104294992317 |
| 30 | 293279485007 |