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 | 2 |
| 2 | 4 |
| 3 | 6 |
| 4 | 14 |
| 5 | 20 |
| 6 | 50 |
| 7 | 70 |
| 8 | 182 |
| 9 | 252 |
| 10 | 672 |
| 11 | 924 |
| 12 | 2508 |
| 13 | 3432 |
| 14 | 9438 |
| 15 | 12870 |
| 16 | 35750 |
| 17 | 48620 |
| 18 | 136136 |
| 19 | 184756 |
| 20 | 520676 |
| 21 | 705432 |
| 22 | 1998724 |
| 23 | 2704156 |
| 24 | 7696444 |
| 25 | 10400600 |
| 26 | 29716000 |
| 27 | 40116600 |
| 28 | 115000920 |
| 29 | 155117520 |
| 30 | 445962870 |