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 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 14 |
| 7 | 40 |
| 8 | 119 |
| 9 | 364 |
| 10 | 1145 |
| 11 | 3688 |
| 12 | 12139 |
| 13 | 40734 |
| 14 | 139071 |
| 15 | 482214 |
| 16 | 1695469 |
| 17 | 6036768 |
| 18 | 21740969 |
| 19 | 79117822 |
| 20 | 290674470 |
| 21 | 1077306351 |
| 22 | 4025068621 |
| 23 | 15151115808 |
| 24 | 57427176992 |
| 25 | 219068962330 |
| 26 | 840708048210 |
| 27 | 3244438898552 |
| 28 | 12586627632549 |
| 29 | 49069788882951 |