| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 156 |
| 3 | 3832 |
| 4 | 101476 |
| 5 | 2653176 |
| 6 | 69537644 |
| 7 | 1821675752 |
| 8 | 47726949876 |
| 9 | 1250396334280 |
| 10 | 32759217743932 |
| 11 | 858260185404312 |
| 12 | 22485600623006756 |
| 13 | 589101327485494424 |
| 14 | 15433894026086119116 |
| 15 | 404353331486123621320 |
| 16 | 10593672372980858817748 |
| 17 | 277544131820420163065832 |
| 18 | 7271392053421269671583068 |
[4,156,3832,101476,2653176,69537644,1821675752, 47726949876,1250396334280,32759217743932, 858260185404312,22485600623006756, 589101327485494424,15433894026086119116, 404353331486123621320,10593672372980858817748, 277544131820420163065832, 7271392053421269671583068] |