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 | 3 |
| 2 | 9 |
| 3 | 28 |
| 4 | 85 |
| 5 | 261 |
| 6 | 797 |
| 7 | 2440 |
| 8 | 7461 |
| 9 | 22827 |
| 10 | 69821 |
| 11 | 213588 |
| 12 | 653345 |
| 13 | 1998573 |
| 14 | 6113529 |
| 15 | 18701072 |
| 16 | 57205769 |
| 17 | 174990195 |
| 18 | 535287793 |
| 19 | 1637423756 |
| 20 | 5008812525 |
| 21 | 15321754293 |
| 22 | 46868623381 |
| 23 | 143369215128 |
| 24 | 438560602669 |
| 25 | 1341539064795 |
| 26 | 4103713486629 |
| 27 | 12553092811972 |