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 | 13 |
| 3 | 21 |
| 4 | 144 |
| 5 | 610 |
| 6 | 1597 |
| 7 | 4181 |
| 8 | 10946 |
| 9 | 17711 |
| 10 | 121393 |
| 11 | 196418 |
| 12 | 317811 |
| 13 | 514229 |
| 14 | 1346269 |
| 15 | 2178309 |
| 16 | 14930352 |
| 17 | 24157817 |
| 18 | 39088169 |
| 19 | 102334155 |
| 20 | 165580141 |
| 21 | 267914296 |
| 22 | 701408733 |
| 23 | 1134903170 |
| 24 | 1836311903 |
| 25 | 2971215073 |
| 26 | 12586269025 |
| 27 | 20365011074 |
| 28 | 32951280099 |