The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 2 |
| 6 | 3 |
| 7 | 0 |
| 8 | 6 |
| 9 | 18 |
| 10 | 12 |
| 11 | 0 |
| 12 | 12 |
| 13 | 72 |
| 14 | 120 |
| 15 | 60 |
| 16 | 0 |
| 17 | 28 |
| 18 | 267 |
| 19 | 780 |
| 20 | 900 |
| 21 | 360 |
| 22 | 0 |
| 23 | 56 |
| 24 | 885 |
| 25 | 4188 |
| 26 | 8400 |
| 27 | 7560 |
| 28 | 2520 |
| 29 | 0 |
| 30 | 120 |
| 31 | 2880 |
| 32 | 20400 |
| 33 | 63000 |
| 34 | 95760 |
| 35 | 70560 |
| 36 | 20160 |
| 37 | 0 |
| 38 | 240 |
| 39 | 9000 |
| 40 | 93120 |
| 41 | 417000 |
| 42 | 952560 |
| 43 | 1164240 |
| 44 | 725760 |
| 45 | 181440 |
| 46 | 0 |
| 47 | 496 |
| 48 | 27915 |
| 49 | 409140 |
| 50 | 2551440 |
| 51 | 8217720 |
| 52 | 14817600 |
| 53 | 15120000 |
| 54 | 8164800 |
| 55 | 1814400 |
| 56 | 0 |
| 57 | 992 |
| 58 | 85233 |
| 59 | 1748220 |
| 60 | 14802900 |
| 61 | 64614960 |
| 62 | 161247240 |
| 63 | 239500800 |
| 64 | 209563200 |
| 65 | 99792000 |
| 66 | 19958400 |
[0,0,1,0,2,3,0,6,18,12,0,12,72,120,60,0,28,267, 780,900,360,0,56,885,4188,8400,7560,2520,0,120, 2880,20400,63000,95760,70560,20160,0,240,9000, 93120,417000,952560,1164240,725760,181440,0,496, 27915,409140,2551440,8217720,14817600,15120000, 8164800,1814400,0,992,85233,1748220,14802900, 64614960,161247240,239500800,209563200,99792000, 19958400] |