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 | 72 |
| 2 | 360 |
| 3 | 2556 |
| 4 | 22572 |
| 5 | 219636 |
| 6 | 2204244 |
| 7 | 22197420 |
| 8 | 222257988 |
| 9 | 2207645892 |
| 10 | 21754722852 |
| 11 | 212845625820 |
| 12 | 2069408197476 |
| 13 | 20010127994676 |
| 14 | 192565336573476 |
| 15 | 1845376043710284 |
| 16 | 17619057807964452 |
| 17 | 167667905660138532 |
| 18 | 1590879916369856484 |
| 19 | 15054743317985652924 |