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 | 0 |
| 1 | 3 |
| 2 | 12 |
| 3 | 41 |
| 4 | 132 |
| 5 | 413 |
| 6 | 1272 |
| 7 | 3881 |
| 8 | 11772 |
| 9 | 35573 |
| 10 | 107232 |
| 11 | 322721 |
| 12 | 970212 |
| 13 | 2914733 |
| 14 | 8752392 |
| 15 | 26273561 |
| 16 | 78853452 |
| 17 | 236625893 |
| 18 | 710008752 |
| 19 | 2130288401 |
| 20 | 6391389492 |
| 21 | 19175217053 |
| 22 | 57527748312 |
| 23 | 172587439241 |
| 24 | 517770706332 |
| 25 | 1553328896213 |
| 26 | 4660020243072 |
| 27 | 13980127838081 |