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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 14 |
| 7 | 35 |
| 8 | 91 |
| 9 | 268 |
| 10 | 864 |
| 11 | 2833 |
| 12 | 9279 |
| 13 | 30670 |
| 14 | 102975 |
| 15 | 351148 |
| 16 | 1212886 |
| 17 | 4232714 |
| 18 | 14900843 |
| 19 | 52865511 |
| 20 | 188871400 |
| 21 | 679029570 |
| 22 | 2455099043 |
| 23 | 8922220725 |
| 24 | 32576194260 |
| 25 | 119447959183 |
| 26 | 439700905503 |
| 27 | 1624436294053 |
| 28 | 6021371511844 |
| 29 | 22388679839583 |
| 30 | 83484414608203 |