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 | 2 |
| 1 | 7 |
| 2 | 24 |
| 3 | 85 |
| 4 | 308 |
| 5 | 1134 |
| 6 | 4224 |
| 7 | 15873 |
| 8 | 60060 |
| 9 | 228514 |
| 10 | 873392 |
| 11 | 3350802 |
| 12 | 12896744 |
| 13 | 49774300 |
| 14 | 192559680 |
| 15 | 746503065 |
| 16 | 2899328940 |
| 17 | 11279096730 |
| 18 | 43942760400 |
| 19 | 171424529430 |
| 20 | 669540282840 |
| 21 | 2617890571140 |
| 22 | 10246047127680 |
| 23 | 40137974797050 |
| 24 | 157368305973528 |
| 25 | 617467192984404 |
| 26 | 2424490605524064 |