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 | 4 |
| 3 | 21 |
| 4 | 82 |
| 5 | 275 |
| 6 | 836 |
| 7 | 2373 |
| 8 | 6406 |
| 9 | 16647 |
| 10 | 41992 |
| 11 | 103433 |
| 12 | 249866 |
| 13 | 593931 |
| 14 | 1392652 |
| 15 | 3227661 |
| 16 | 7405582 |
| 17 | 16842767 |
| 18 | 38010896 |
| 19 | 85196817 |
| 20 | 189792274 |
| 21 | 420478995 |
| 22 | 926941204 |
| 23 | 2034237461 |
| 24 | 4445962262 |
| 25 | 9680453655 |
| 26 | 21005074456 |
| 27 | 45432700953 |
| 28 | 97978941466 |
| 29 | 210721832987 |
| 30 | 452045307932 |