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 | 0 |
| 2 | 1 |
| 3 | 9 |
| 4 | 95 |
| 5 | 1220 |
| 6 | 18694 |
| 7 | 334369 |
| 8 | 6852460 |
| 9 | 158479488 |
| 10 | 4085349936 |
| 11 | 116193701393 |
| 12 | 3615197586912 |
| 13 | 122165572502324 |
| 14 | 4456126288810624 |
| 15 | 174520484866919385 |
| 16 | 7304657490838627072 |
| 17 | 325420940777809245152 |
| 18 | 15374940186972235659264 |
| 19 | 767898500931828204443769 |