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) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 20 |
| 3 | 71 |
| 4 | 235 |
| 5 | 744 |
| 6 | 2285 |
| 7 | 6865 |
| 8 | 20284 |
| 9 | 59155 |
| 10 | 170711 |
| 11 | 488400 |
| 12 | 1387225 |
| 13 | 3916061 |
| 14 | 10996580 |
| 15 | 30737759 |
| 16 | 85573315 |
| 17 | 237387960 |
| 18 | 656451269 |
| 19 | 1810142185 |
| 20 | 4978643596 |
| 21 | 13661617195 |
| 22 | 37409025455 |
| 23 | 102238082976 |
| 24 | 278920277425 |
| 25 | 759695287349 |