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 | 2 |
| 2 | 15 |
| 3 | 132 |
| 4 | 1565 |
| 5 | 22918 |
| 6 | 400939 |
| 7 | 8160008 |
| 8 | 189453369 |
| 9 | 4942271754 |
| 10 | 143128015943 |
| 11 | 4556517918604 |
| 12 | 158167223290453 |
| 13 | 5945611873120910 |
| 14 | 240619359452963427 |
| 15 | 10430922482219093520 |
| 16 | 482234053313600047217 |
| 17 | 23683786738296923795986 |