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 | 91 |
| 3 | 1470 |
| 4 | 26565 |
| 5 | 514206 |
| 6 | 10426416 |
| 7 | 218618940 |
| 8 | 4701550770 |
| 9 | 103134123820 |
| 10 | 2298706645235 |
| 11 | 51909777109596 |
| 12 | 1185134654128425 |
| 13 | 27309853977084000 |
| 14 | 634361032466470620 |
| 15 | 14837590383963667320 |
| 16 | 349163392095422769942 |
| 17 | 8260872214482785042145 |
| 18 | 196380752260155290992675 |