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 | 1 |
| 2 | 6 |
| 3 | 46 |
| 4 | 436 |
| 5 | 4956 |
| 6 | 65776 |
| 7 | 996976 |
| 8 | 16957536 |
| 9 | 319259296 |
| 10 | 6581662336 |
| 11 | 147290942976 |
| 12 | 3552885191296 |
| 13 | 91827536814976 |
| 14 | 2530228890080256 |
| 15 | 74003737259670016 |
| 16 | 2288810287491774976 |
| 17 | 74607500831801289216 |
| 18 | 2555587654482227055616 |
| 19 | 91746983502042106018816 |