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 | 5 |
| 4 | 14 |
| 5 | 89 |
| 6 | 474 |
| 7 | 3499 |
| 8 | 27040 |
| 9 | 253161 |
| 10 | 2426300 |
| 11 | 27596051 |
| 12 | 323960856 |
| 13 | 4277055925 |
| 14 | 59041067344 |
| 15 | 898062119655 |
| 16 | 14172430400864 |
| 17 | 243919993681649 |
| 18 | 4347177953716080 |
| 19 | 83224487266425811 |
| 20 | 1653277176082392040 |
| 21 | 34961357216796300381 |
| 22 | 763702067489722288136 |