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 | 19 |
| 3 | 68 |
| 4 | 207 |
| 5 | 997 |
| 6 | 4210 |
| 7 | 16658 |
| 8 | 68769 |
| 9 | 284867 |
| 10 | 1170146 |
| 11 | 4807394 |
| 12 | 19787328 |
| 13 | 81424284 |
| 14 | 334903296 |
| 15 | 1377738399 |
| 16 | 5668140481 |
| 17 | 23317788357 |
| 18 | 95926011656 |
| 19 | 394630220291 |
| 20 | 1623463820564 |
| 21 | 6678736090662 |
| 22 | 27475550500449 |
| 23 | 113031264492453 |