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 | 1 |
| 2 | 15 |
| 3 | 155 |
| 4 | 1410 |
| 5 | 12165 |
| 6 | 102548 |
| 7 | 856205 |
| 8 | 7128420 |
| 9 | 59386655 |
| 10 | 495973610 |
| 11 | 4156326090 |
| 12 | 34965061950 |
| 13 | 295326872685 |
| 14 | 2504471904060 |
| 15 | 21322339850120 |
| 16 | 182220932483936 |
| 17 | 1562911922345700 |
| 18 | 13451387178653575 |
| 19 | 116149864521206475 |
| 20 | 1006036370555080950 |
| 21 | 8739349976276626707 |
| 22 | 76128234963921173340 |