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 | 3 |
| 1 | 4 |
| 2 | 9 |
| 3 | 24 |
| 4 | 70 |
| 5 | 216 |
| 6 | 693 |
| 7 | 2288 |
| 8 | 7722 |
| 9 | 26520 |
| 10 | 92378 |
| 11 | 325584 |
| 12 | 1158924 |
| 13 | 4160240 |
| 14 | 15043725 |
| 15 | 54747360 |
| 16 | 200360130 |
| 17 | 736928280 |
| 18 | 2722540590 |
| 19 | 10098646800 |
| 20 | 37594507860 |
| 21 | 140415097680 |
| 22 | 526024740930 |
| 23 | 1976023374624 |
| 24 | 7441754696100 |
| 25 | 28091245875056 |
| 26 | 106268257060308 |
| 27 | 402815053582368 |