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 | 8 |
| 3 | 102 |
| 4 | 1580 |
| 5 | 27193 |
| 6 | 499828 |
| 7 | 9609372 |
| 8 | 190869948 |
| 9 | 3886281300 |
| 10 | 80681111940 |
| 11 | 1701418017390 |
| 12 | 36345240847188 |
| 13 | 784821812522062 |
| 14 | 17103169093916120 |
| 15 | 375670490644949624 |
| 16 | 8308349385885678684 |
| 17 | 184856293637482503660 |
| 18 | 4134886240989315235840 |
| 19 | 92928784113832360511800 |
| 20 | 2097399158679611824619120 |