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 | 7 |
| 2 | 55 |
| 3 | 471 |
| 4 | 4251 |
| 5 | 39733 |
| 6 | 380731 |
| 7 | 3716695 |
| 8 | 36808723 |
| 9 | 368750757 |
| 10 | 3728940249 |
| 11 | 38003358693 |
| 12 | 389866749975 |
| 13 | 4022124746409 |
| 14 | 41697566691555 |
| 15 | 434124925278807 |
| 16 | 4536783726146499 |
| 17 | 47569453938399445 |
| 18 | 500266519237489357 |
| 19 | 5275183203229043221 |
| 20 | 55760274296452936741 |