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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 7 |
| 5 | 19 |
| 6 | 56 |
| 7 | 180 |
| 8 | 596 |
| 9 | 2015 |
| 10 | 6904 |
| 11 | 23923 |
| 12 | 83755 |
| 13 | 296084 |
| 14 | 1056095 |
| 15 | 3797790 |
| 16 | 13757665 |
| 17 | 50164787 |
| 18 | 183980036 |
| 19 | 678215028 |
| 20 | 2511483176 |
| 21 | 9337575130 |
| 22 | 34840575458 |
| 23 | 130412367572 |
| 24 | 489546890178 |
| 25 | 1842438724560 |
| 26 | 6950471604901 |
| 27 | 26276784902865 |
| 28 | 99539079724648 |
| 29 | 377759500611913 |
| 30 | 1436093975018569 |
| 31 | 5468247624237042 |
| 32 | 20853026397347178 |