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 | 1 |
| 2 | 8 |
| 3 | 50 |
| 4 | 286 |
| 5 | 1566 |
| 6 | 8358 |
| 7 | 43870 |
| 8 | 227606 |
| 9 | 1170926 |
| 10 | 5985958 |
| 11 | 30454590 |
| 12 | 154371126 |
| 13 | 780246286 |
| 14 | 3934789958 |
| 15 | 19808175710 |
| 16 | 99577765846 |
| 17 | 500036345646 |
| 18 | 2508771728358 |
| 19 | 12578218511230 |
| 20 | 63028531771766 |
| 21 | 315692415197006 |
| 22 | 1580661100289158 |
| 23 | 7912101596565150 |
| 24 | 39595692359108886 |