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 | 2 |
| 2 | 1 |
| 3 | 4 |
| 4 | 7 |
| 5 | 24 |
| 6 | 62 |
| 7 | 216 |
| 8 | 710 |
| 9 | 2570 |
| 10 | 9215 |
| 11 | 34146 |
| 12 | 126853 |
| 13 | 477182 |
| 14 | 1802673 |
| 15 | 6853152 |
| 16 | 26153758 |
| 17 | 100215818 |
| 18 | 385226201 |
| 19 | 1485248464 |
| 20 | 5741275753 |
| 21 | 22246121356 |
| 22 | 86383454582 |
| 23 | 336094015456 |
| 24 | 1309998396933 |
| 25 | 5114454089528 |
| 26 | 19998173763831 |
| 27 | 78306021876974 |
| 28 | 307022186132259 |
| 29 | 1205243906123956 |
| 30 | 4736694016531135 |