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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 26 |
| 6 | 102 |
| 7 | 420 |
| 8 | 1793 |
| 9 | 7854 |
| 10 | 35106 |
| 11 | 159492 |
| 12 | 734334 |
| 13 | 3418892 |
| 14 | 16068532 |
| 15 | 76135112 |
| 16 | 363283763 |
| 17 | 1744135306 |
| 18 | 8419281306 |
| 19 | 40838500796 |
| 20 | 198950342814 |
| 21 | 972999755364 |
| 22 | 4775441138580 |
| 23 | 23513016382120 |
| 24 | 116111875760294 |
| 25 | 574927064750460 |
| 26 | 2853800953323468 |
| 27 | 14197997592237912 |
| 28 | 70786396399962476 |
| 29 | 353611516341840008 |
| 30 | 1769694222850151128 |