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 | 5 |
| 3 | 21 |
| 4 | 70 |
| 5 | 214 |
| 6 | 614 |
| 7 | 1703 |
| 8 | 4619 |
| 9 | 12363 |
| 10 | 32812 |
| 11 | 86636 |
| 12 | 228012 |
| 13 | 598893 |
| 14 | 1571089 |
| 15 | 4118305 |
| 16 | 10790194 |
| 17 | 28262594 |
| 18 | 74014290 |
| 19 | 193807315 |
| 20 | 507451415 |
| 21 | 1328617751 |
| 22 | 3478516440 |
| 23 | 9107117016 |
| 24 | 23843134680 |
| 25 | 62422772569 |
| 26 | 163425968669 |
| 27 | 427856404653 |