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 | 3 |
| 3 | 9 |
| 4 | 28 |
| 5 | 87 |
| 6 | 272 |
| 7 | 850 |
| 8 | 2659 |
| 9 | 8318 |
| 10 | 26025 |
| 11 | 81427 |
| 12 | 254777 |
| 13 | 797175 |
| 14 | 2494307 |
| 15 | 7804529 |
| 16 | 24419909 |
| 17 | 76408475 |
| 18 | 239077739 |
| 19 | 748060606 |
| 20 | 2340639096 |
| 21 | 7323726778 |
| 22 | 22915525377 |
| 23 | 71701378526 |
| 24 | 224349545236 |
| 25 | 701976998795 |
| 26 | 2196446204672 |
| 27 | 6872555567553 |
| 28 | 21503836486190 |
| 29 | 67284284442622 |
| 30 | 210528708959146 |