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 | 2 |
| 2 | 7 |
| 3 | 28 |
| 4 | 130 |
| 5 | 702 |
| 6 | 4384 |
| 7 | 31516 |
| 8 | 260068 |
| 9 | 2445372 |
| 10 | 25796360 |
| 11 | 299286550 |
| 12 | 3751803964 |
| 13 | 50211590696 |
| 14 | 712746859372 |
| 15 | 10697637496288 |
| 16 | 169490803535680 |
| 17 | 2830925427778810 |
| 18 | 49785906936838240 |
| 19 | 921273098388684878 |
| 20 | 17944637546960083042 |
| 21 | 368472898102440537484 |
| 22 | 7993616254370783660414 |
| 23 | 183539682466936703629744 |