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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 26 |
| 6 | 52 |
| 7 | 1066 |
| 8 | 1667 |
| 9 | 2188 |
| 10 | 32152 |
| 11 | 67834 |
| 12 | 423176 |
| 13 | 437576 |
| 14 | 14752936 |
| 15 | 26513692 |
| 16 | 27711772 |
| 17 | 33274388 |
| 18 | 320785556 |
| 19 | 1065805109 |
| 20 | 9012701786 |
| 21 | 9256436186 |
| 22 | 12814126552 |
| 23 | 18814619428 |
| 24 | 201241053056 |
| 25 | 478999841578 |
| 26 | 670919564984 |
| 27 | 18432110906024 |
| 28 | 158312796835916 |
| 29 | 278737550525722 |