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 | 14 |
| 5 | 42 |
| 6 | 130 |
| 7 | 415 |
| 8 | 1368 |
| 9 | 4603 |
| 10 | 15788 |
| 11 | 54863 |
| 12 | 193112 |
| 13 | 686049 |
| 14 | 2459942 |
| 15 | 8881931 |
| 16 | 32292148 |
| 17 | 118038070 |
| 18 | 433790834 |
| 19 | 1601042055 |
| 20 | 5934546466 |
| 21 | 22074679425 |
| 22 | 82399006636 |
| 23 | 308471888767 |
| 24 | 1158175006638 |
| 25 | 4359154749776 |
| 26 | 16447468190380 |
| 27 | 62188658733901 |