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 | 2 |
| 2 | 23 |
| 3 | 118 |
| 4 | 564 |
| 5 | 2793 |
| 6 | 14394 |
| 7 | 71564 |
| 8 | 359659 |
| 9 | 1808256 |
| 10 | 9076074 |
| 11 | 45607585 |
| 12 | 229124216 |
| 13 | 1151098126 |
| 14 | 5783024867 |
| 15 | 29053401570 |
| 16 | 145961054556 |
| 17 | 733293062029 |
| 18 | 3683989357618 |
| 19 | 18507978344520 |
| 20 | 92982190589347 |
| 21 | 467132961135876 |