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A291388 as a simple table
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 44 |
| 3 | 262 |
| 4 | 1504 |
| 5 | 8416 |
| 6 | 46208 |
| 7 | 250016 |
| 8 | 1337088 |
| 9 | 7083264 |
| 10 | 37229568 |
| 11 | 194383360 |
| 12 | 1009172480 |
| 13 | 5213634560 |
| 14 | 26819756032 |
| 15 | 137445318656 |
| 16 | 702021435392 |
| 17 | 3574958587904 |
| 18 | 18156130926592 |
| 19 | 91985567678464 |
| 20 | 465004476235776 |
| 21 | 2345955741401088 |
| 22 | 11813573860786176 |
[1,7,44,262,1504,8416,46208,250016,1337088, 7083264,37229568,194383360,1009172480,5213634560, 26819756032,137445318656,702021435392, 3574958587904,18156130926592,91985567678464, 465004476235776,2345955741401088, 11813573860786176] |