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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 14 |
| 4 | 45 |
| 5 | 140 |
| 6 | 428 |
| 7 | 1297 |
| 8 | 3912 |
| 9 | 11770 |
| 10 | 35365 |
| 11 | 106184 |
| 12 | 318696 |
| 13 | 956321 |
| 14 | 2869340 |
| 15 | 8608630 |
| 16 | 25826877 |
| 17 | 77482228 |
| 18 | 232449268 |
| 19 | 697351985 |
| 20 | 2092062720 |
| 21 | 6276199106 |
| 22 | 18828615029 |
| 23 | 56485873744 |
| 24 | 169457667600 |
| 25 | 508373077825 |
| 26 | 1525119354868 |