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 | 3 |
| 2 | 12 |
| 3 | 64 |
| 4 | 372 |
| 5 | 2319 |
| 6 | 15105 |
| 7 | 101649 |
| 8 | 701073 |
| 9 | 4929657 |
| 10 | 35207220 |
| 11 | 254690517 |
| 12 | 1862325262 |
| 13 | 13742311074 |
| 14 | 102204992352 |
| 15 | 765328009950 |
| 16 | 5765316776550 |
| 17 | 43661497944861 |
| 18 | 332217854059362 |
| 19 | 2538540859615095 |
| 20 | 19471592691620310 |
| 21 | 149871698475060433 |
| 22 | 1157188723053901449 |