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 | 11 |
| 3 | 38 |
| 4 | 139 |
| 5 | 506 |
| 6 | 1881 |
| 7 | 7019 |
| 8 | 26449 |
| 9 | 100111 |
| 10 | 381060 |
| 11 | 1455872 |
| 12 | 5583063 |
| 13 | 21472978 |
| 14 | 82810941 |
| 15 | 320094718 |
| 16 | 1239852777 |
| 17 | 4811195125 |
| 18 | 18700386300 |
| 19 | 72792837115 |
| 20 | 283731854748 |
| 21 | 1107273926974 |
| 22 | 4325975674774 |
| 23 | 16918209611354 |