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 | 3 |
| 4 | 10 |
| 5 | 35 |
| 6 | 128 |
| 7 | 483 |
| 8 | 1866 |
| 9 | 7344 |
| 10 | 29342 |
| 11 | 118701 |
| 12 | 485249 |
| 13 | 2001467 |
| 14 | 8319019 |
| 15 | 34810084 |
| 16 | 146519286 |
| 17 | 619939204 |
| 18 | 2635257950 |
| 19 | 11248889770 |
| 20 | 48198305528 |
| 21 | 207222648334 |
| 22 | 893704746508 |
| 23 | 3865335575201 |
| 24 | 16761606193951 |
| 25 | 72860178774410 |
| 26 | 317418310631983 |
| 27 | 1385703968792040 |