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 | 10 |
| 2 | 84 |
| 3 | 715 |
| 4 | 6188 |
| 5 | 54264 |
| 6 | 480700 |
| 7 | 4292145 |
| 8 | 38567100 |
| 9 | 348330136 |
| 10 | 3159461968 |
| 11 | 28760021745 |
| 12 | 262596783764 |
| 13 | 2403979904200 |
| 14 | 22057981462440 |
| 15 | 202802465047245 |
| 16 | 1867897112363100 |
| 17 | 17231414395464984 |
| 18 | 159186450151978480 |
| 19 | 1472474663905800940 |
| 20 | 13636219405675529520 |