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 | 5 |
| 3 | 18 |
| 4 | 86 |
| 5 | 414 |
| 6 | 2137 |
| 7 | 11322 |
| 8 | 61731 |
| 9 | 343363 |
| 10 | 1943488 |
| 11 | 11157558 |
| 12 | 64841876 |
| 13 | 380777798 |
| 14 | 2256500525 |
| 15 | 13479035412 |
| 16 | 81085573679 |
| 17 | 490856939495 |
| 18 | 2988208167015 |
| 19 | 18283978901128 |
| 20 | 112390059830932 |
| 21 | 693750864437218 |
| 22 | 4298745830972544 |