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 | 1 |
| 3 | 4 |
| 4 | 5 |
| 5 | 6 |
| 6 | 142 |
| 7 | 428 |
| 8 | 1269 |
| 9 | 3874 |
| 10 | 20336 |
| 11 | 114522 |
| 12 | 429002 |
| 13 | 1743184 |
| 14 | 6456192 |
| 15 | 23749014 |
| 16 | 93997909 |
| 17 | 368890906 |
| 18 | 1122546076 |
| 19 | 4496925530 |
| 20 | 17437145160 |
| 21 | 76147395524 |
| 22 | 310155556998 |
| 23 | 1417665712388 |
| 24 | 5528899930962 |
| 25 | 21923449788406 |
| 26 | 82833896451112 |
| 27 | 347234278501138 |