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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 25 |
| 7 | 68 |
| 8 | 187 |
| 9 | 534 |
| 10 | 1544 |
| 11 | 4554 |
| 12 | 13576 |
| 13 | 40968 |
| 14 | 124681 |
| 15 | 382636 |
| 16 | 1182116 |
| 17 | 3674674 |
| 18 | 11483243 |
| 19 | 36057516 |
| 20 | 113701968 |
| 21 | 359927638 |
| 22 | 1143327888 |
| 23 | 3643379152 |
| 24 | 11643793399 |
| 25 | 37311200060 |
| 26 | 119852247220 |
| 27 | 385864664018 |
| 28 | 1244896820476 |