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 | 3 |
| 2 | 13 |
| 3 | 51 |
| 4 | 201 |
| 5 | 783 |
| 6 | 3039 |
| 7 | 11763 |
| 8 | 45481 |
| 9 | 175803 |
| 10 | 679779 |
| 11 | 2630367 |
| 12 | 10187659 |
| 13 | 39500373 |
| 14 | 153329913 |
| 15 | 595883763 |
| 16 | 2318471289 |
| 17 | 9030982491 |
| 18 | 35216266947 |
| 19 | 137469149451 |
| 20 | 537152523711 |
| 21 | 2100857828193 |
| 22 | 8223917499477 |
| 23 | 32219655346719 |
| 24 | 126328429601451 |
| 25 | 495676719721953 |
| 26 | 1946227355491909 |