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 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 40 |
| 5 | 106 |
| 6 | 281 |
| 7 | 685 |
| 8 | 1690 |
| 9 | 4050 |
| 10 | 9496 |
| 11 | 21908 |
| 12 | 49902 |
| 13 | 111740 |
| 14 | 247465 |
| 15 | 541353 |
| 16 | 1171070 |
| 17 | 2507602 |
| 18 | 5319085 |
| 19 | 11178947 |
| 20 | 23298878 |
| 21 | 48169708 |
| 22 | 98834943 |
| 23 | 201335651 |
| 24 | 407345067 |
| 25 | 818767703 |
| 26 | 1635528657 |
| 27 | 3247634227 |
| 28 | 6412057831 |
| 29 | 12590738729 |
| 30 | 24593652845 |