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 | 24 |
| 2 | 70 |
| 3 | 206 |
| 4 | 608 |
| 5 | 1798 |
| 6 | 5324 |
| 7 | 15780 |
| 8 | 46806 |
| 9 | 138918 |
| 10 | 412508 |
| 11 | 1225432 |
| 12 | 3641690 |
| 13 | 10825628 |
| 14 | 32190154 |
| 15 | 95741294 |
| 16 | 284820048 |
| 17 | 847475910 |
| 18 | 2522096172 |
| 19 | 7507000776 |
| 20 | 22347852666 |
| 21 | 66537181776 |
| 22 | 198128815230 |
| 23 | 590039959434 |
| 24 | 1757365514652 |