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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 52 |
| 6 | 203 |
| 7 | 876 |
| 8 | 4111 |
| 9 | 20648 |
| 10 | 109299 |
| 11 | 601492 |
| 12 | 3403127 |
| 13 | 19628064 |
| 14 | 114700315 |
| 15 | 676207628 |
| 16 | 4010090463 |
| 17 | 23874362200 |
| 18 | 142508723651 |
| 19 | 852124263684 |
| 20 | 5101098232519 |
| 21 | 30560194493456 |
| 22 | 183176170057707 |
| 23 | 1098318779272060 |
| 24 | 6586964947803695 |
| 25 | 39510014478620232 |
| 26 | 237013033135668883 |