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 | 0 |
| 1 | 1 |
| 2 | 10 |
| 3 | 155 |
| 4 | 2770 |
| 5 | 54465 |
| 6 | 1136402 |
| 7 | 24723000 |
| 8 | 554540590 |
| 9 | 12732651160 |
| 10 | 297795974970 |
| 11 | 7069820334023 |
| 12 | 169926110309380 |
| 13 | 4126836768095315 |
| 14 | 101114499262401970 |
| 15 | 2496432769621336865 |
| 16 | 62045482307629427354 |
| 17 | 1551083997228106913910 |
| 18 | 38976793037598171500920 |