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 | 3 |
| 2 | 11 |
| 3 | 51 |
| 4 | 299 |
| 5 | 2163 |
| 6 | 18731 |
| 7 | 189171 |
| 8 | 2183339 |
| 9 | 28349043 |
| 10 | 408990251 |
| 11 | 6490530291 |
| 12 | 112366270379 |
| 13 | 2107433393523 |
| 14 | 42565371881771 |
| 15 | 921132763911411 |
| 16 | 21262618727925419 |
| 17 | 521483068116543603 |
| 18 | 13542138653027381291 |
| 19 | 371206349277313644531 |