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 | 3 |
| 2 | 3 |
| 3 | 7 |
| 4 | 23 |
| 5 | 69 |
| 6 | 228 |
| 7 | 766 |
| 8 | 2642 |
| 9 | 9309 |
| 10 | 33382 |
| 11 | 120629 |
| 12 | 439752 |
| 13 | 1613135 |
| 14 | 5953061 |
| 15 | 22075011 |
| 16 | 82204128 |
| 17 | 307213215 |
| 18 | 1151820825 |
| 19 | 4330858682 |
| 20 | 16326297768 |
| 21 | 61690058385 |