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 | 3 |
| 2 | 54 |
| 3 | 1360 |
| 4 | 41405 |
| 5 | 1404102 |
| 6 | 51126740 |
| 7 | 1957600876 |
| 8 | 77812428681 |
| 9 | 3183756066040 |
| 10 | 133302637049516 |
| 11 | 5687179333193904 |
| 12 | 246453229359401883 |
| 13 | 10821674290217357756 |
| 14 | 480561612716912592360 |
| 15 | 21549547977144582750304 |
| 16 | 974600584933918611940825 |
| 17 | 44409401763058366474029057 |