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 | 0 |
| 1 | 1 |
| 2 | 23 |
| 3 | 397 |
| 4 | 6095 |
| 5 | 87781 |
| 6 | 1214423 |
| 7 | 16344637 |
| 8 | 1263934 |
| 9 | 443884970 |
| 10 | 10042515022 |
| 11 | 172385029466 |
| 12 | 2639243694814 |
| 13 | 3425068947279 |
| 14 | 144668963799141 |
| 15 | 2875277066339415 |
| 16 | 1085339440747772 |
| 17 | 196822992743261908 |
| 18 | 4383664026916317980 |
| 19 | 13684547128550195393 |
| 20 | 470010017784675076171 |