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 | 10 |
| 3 | 21 |
| 4 | 199 |
| 5 | 220 |
| 6 | 8999 |
| 7 | 9219 |
| 8 | 91970 |
| 9 | 193159 |
| 10 | 1830401 |
| 11 | 2023560 |
| 12 | 82772801 |
| 13 | 84796361 |
| 14 | 845940050 |
| 15 | 1776676461 |
| 16 | 16836028199 |
| 17 | 18612704660 |
| 18 | 761344214599 |
| 19 | 779956919259 |
| 20 | 7780956487930 |
| 21 | 16341869895119 |
| 22 | 154857785544001 |
| 23 | 171199655439120 |
| 24 | 7002844003108801 |