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 | 2 |
| 2 | 6 |
| 3 | 16 |
| 4 | 42 |
| 5 | 108 |
| 6 | 274 |
| 7 | 688 |
| 8 | 1714 |
| 9 | 4244 |
| 10 | 10458 |
| 11 | 25672 |
| 12 | 62826 |
| 13 | 153372 |
| 14 | 373666 |
| 15 | 908896 |
| 16 | 2207842 |
| 17 | 5357348 |
| 18 | 12988074 |
| 19 | 31464568 |
| 20 | 76179354 |
| 21 | 184347564 |
| 22 | 445923058 |
| 23 | 1078290832 |
| 24 | 2606699026 |
| 25 | 6300077492 |
| 26 | 15223631226 |
| 27 | 36780894376 |
| 28 | 88852528842 |
| 29 | 214620169788 |