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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 18 |
| 6 | 40 |
| 7 | 91 |
| 8 | 210 |
| 9 | 492 |
| 10 | 1165 |
| 11 | 2786 |
| 12 | 6710 |
| 13 | 16267 |
| 14 | 39650 |
| 15 | 97108 |
| 16 | 238824 |
| 17 | 589521 |
| 18 | 1459960 |
| 19 | 3626213 |
| 20 | 9030450 |
| 21 | 22542396 |
| 22 | 56393792 |
| 23 | 141358274 |
| 24 | 354975429 |
| 25 | 892893120 |
| 26 | 2249412290 |
| 27 | 5674891000 |
| 28 | 14335757256 |
| 29 | 36259245522 |
| 30 | 91815545800 |