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 | 48 |
| 2 | 1128 |
| 3 | 17344 |
| 4 | 196836 |
| 5 | 1764192 |
| 6 | 13051008 |
| 7 | 82244736 |
| 8 | 452197434 |
| 9 | 2210431056 |
| 10 | 9753024192 |
| 11 | 39328459968 |
| 12 | 146436844568 |
| 13 | 507826976160 |
| 14 | 1652238451200 |
| 15 | 5074887938688 |
| 16 | 14794635174459 |
| 17 | 41126600601168 |
| 18 | 109456398969568 |
| 19 | 279899944411776 |
| 20 | 689873759134308 |