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 | 0 |
| 1 | 2 |
| 2 | 110 |
| 3 | 2002 |
| 4 | 20020 |
| 5 | 136136 |
| 6 | 705432 |
| 7 | 2984520 |
| 8 | 10786908 |
| 9 | 34370050 |
| 10 | 98768670 |
| 11 | 260390130 |
| 12 | 638110200 |
| 13 | 1468635168 |
| 14 | 3200871520 |
| 15 | 6650874912 |
| 16 | 13248113736 |
| 17 | 25415833170 |
| 18 | 47143878782 |
| 19 | 84832157410 |
| 20 | 148507792972 |
| 21 | 253549890440 |
| 22 | 423093671000 |
| 23 | 691331713800 |
| 24 | 1107985378500 |