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 | 0 |
| 2 | 13 |
| 3 | 3 |
| 4 | 68 |
| 5 | 231 |
| 6 | 887 |
| 7 | 3307 |
| 8 | 13910 |
| 9 | 55501 |
| 10 | 228947 |
| 11 | 947582 |
| 12 | 3930953 |
| 13 | 16243210 |
| 14 | 67305782 |
| 15 | 278635282 |
| 16 | 1154097789 |
| 17 | 4780226279 |
| 18 | 19802856358 |
| 19 | 82032779562 |
| 20 | 339845971291 |
| 21 | 1407890373170 |
| 22 | 5832655811595 |
| 23 | 24163797280825 |
| 24 | 100107714077232 |