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 | 5 |
| 2 | 15 |
| 3 | 39 |
| 4 | 102 |
| 5 | 267 |
| 6 | 699 |
| 7 | 1830 |
| 8 | 4791 |
| 9 | 12543 |
| 10 | 32838 |
| 11 | 85971 |
| 12 | 225075 |
| 13 | 589254 |
| 14 | 1542687 |
| 15 | 4038807 |
| 16 | 10573734 |
| 17 | 27682395 |
| 18 | 72473451 |
| 19 | 189737958 |
| 20 | 496740423 |
| 21 | 1300483311 |
| 22 | 3404709510 |
| 23 | 8913645219 |
| 24 | 23336226147 |
| 25 | 61095033222 |
| 26 | 159948873519 |
| 27 | 418751587335 |
| 28 | 1096305888486 |
| 29 | 2870166078123 |