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 | 3 |
| 1 | 14 |
| 2 | 59 |
| 3 | 242 |
| 4 | 982 |
| 5 | 3964 |
| 6 | 15955 |
| 7 | 64106 |
| 8 | 257282 |
| 9 | 1031780 |
| 10 | 4135518 |
| 11 | 16569204 |
| 12 | 66365964 |
| 13 | 265761016 |
| 14 | 1064046979 |
| 15 | 4259609626 |
| 16 | 17050224394 |
| 17 | 68241838036 |
| 18 | 273110643754 |
| 19 | 1092947507356 |
| 20 | 4373580244084 |
| 21 | 17500703480776 |