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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 232 |
| 8 | 764 |
| 9 | 2620 |
| 10 | 9496 |
| 11 | 33076 |
| 12 | 112428 |
| 13 | 372436 |
| 14 | 1214976 |
| 15 | 3913582 |
| 16 | 12529522 |
| 17 | 39989374 |
| 18 | 127728664 |
| 19 | 409169795 |
| 20 | 1317486613 |
| 21 | 4256424244 |
| 22 | 13780938480 |
| 23 | 44667060684 |
| 24 | 144831314468 |
| 25 | 469535390016 |
| 26 | 1521506451968 |
| 27 | 4927356770176 |
| 28 | 15947637013296 |