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 | 7 |
| 3 | 69 |
| 4 | 793 |
| 5 | 9946 |
| 6 | 131993 |
| 7 | 1822288 |
| 8 | 25904165 |
| 9 | 376601883 |
| 10 | 5573626462 |
| 11 | 83692267478 |
| 12 | 1271883556731 |
| 13 | 19525467196176 |
| 14 | 302346907361688 |
| 15 | 4716814859429384 |
| 16 | 74065892877777885 |
| 17 | 1169701519598447641 |
| 18 | 18566836447453815317 |
| 19 | 296053851068485920563 |
| 20 | 4739945317989532651858 |