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 | 2 |
| 4 | 4 |
| 5 | 11 |
| 6 | 30 |
| 7 | 122 |
| 8 | 336 |
| 9 | 1412 |
| 10 | 15129 |
| 11 | 44561 |
| 12 | 417542 |
| 13 | 2479120 |
| 14 | 7540843 |
| 15 | 35983502 |
| 16 | 451454834 |
| 17 | 5313515136 |
| 18 | 16809858904 |
| 19 | 190077477328 |
| 20 | 1124302066470 |
| 21 | 3521811953565 |
| 22 | 38563707677633 |
| 23 | 240966297786218 |
| 24 | 3192420711942298 |
| 25 | 95433674596402663 |
| 26 | 567734580765228356 |