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 | 5 |
| 4 | 12 |
| 5 | 29 |
| 6 | 75 |
| 7 | 191 |
| 8 | 504 |
| 9 | 1339 |
| 10 | 3610 |
| 11 | 9800 |
| 12 | 26881 |
| 13 | 74118 |
| 14 | 205706 |
| 15 | 573514 |
| 16 | 1606107 |
| 17 | 4513830 |
| 18 | 12727944 |
| 19 | 35989960 |
| 20 | 102026638 |
| 21 | 289877828 |
| 22 | 825273050 |
| 23 | 2353794251 |
| 24 | 6724468631 |
| 25 | 19239746730 |
| 26 | 55123700591 |
| 27 | 158133959239 |
| 28 | 454168562921 |
| 29 | 1305796834570 |
| 30 | 3758088009136 |