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 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 56 |
| 7 | 164 |
| 8 | 533 |
| 9 | 1818 |
| 10 | 6473 |
| 11 | 23546 |
| 12 | 87146 |
| 13 | 325737 |
| 14 | 1227708 |
| 15 | 4654284 |
| 16 | 17733539 |
| 17 | 67841448 |
| 18 | 260463500 |
| 19 | 1003087732 |
| 20 | 3873759682 |
| 21 | 14996820360 |
| 22 | 58188678048 |
| 23 | 226235685776 |
| 24 | 881235386179 |
| 25 | 3438462430943 |
| 26 | 13437551253018 |