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 | 3 |
| 3 | 16 |
| 4 | 141 |
| 5 | 1871 |
| 6 | 34951 |
| 7 | 873174 |
| 8 | 27951929 |
| 9 | 1107415549 |
| 10 | 52891809491 |
| 11 | 2987861887924 |
| 12 | 196828568831365 |
| 13 | 14950745148070499 |
| 14 | 1296606974501951743 |
| 15 | 127238563043551898986 |
| 16 | 14012626653816435643633 |
| 17 | 1719136634276882827095009 |
| 18 | 233448782800118609096218891 |