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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 10 |
| 6 | 71 |
| 7 | 444 |
| 8 | 2617 |
| 9 | 14958 |
| 10 | 84063 |
| 11 | 467960 |
| 12 | 2591265 |
| 13 | 14308722 |
| 14 | 78911943 |
| 15 | 435066228 |
| 16 | 2399404345 |
| 17 | 13242035030 |
| 18 | 73150006271 |
| 19 | 404525810928 |
| 20 | 2239684086529 |
| 21 | 12415205896794 |
| 22 | 68905402034311 |
| 23 | 382897019146540 |
| 24 | 2130255439081721 |
| 25 | 11865617032955070 |