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 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 61 |
| 5 | 554 |
| 6 | 6565 |
| 7 | 96677 |
| 8 | 1716730 |
| 9 | 36072181 |
| 10 | 881242577 |
| 11 | 24674241834 |
| 12 | 783024550969 |
| 13 | 27896201305769 |
| 14 | 1106485798248706 |
| 15 | 48517267642373105 |
| 16 | 2337333266369553253 |
| 17 | 123040664089658462650 |
| 18 | 7043260281573138384701 |
| 19 | 436533086101058798529933 |