The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 6 |
| 5 | 20 |
| 6 | 50 |
| 7 | 96 |
| 8 | 168 |
| 9 | 264 |
| 10 | 396 |
| 11 | 560 |
| 12 | 770 |
| 13 | 1020 |
| 14 | 1326 |
| 15 | 1680 |
| 16 | 2100 |
| 17 | 2576 |
| 18 | 3128 |
| 19 | 3744 |
| 20 | 4446 |
| 21 | 5220 |
| 22 | 5880 |
| 23 | 7040 |
| 24 | 8096 |
| 25 | 9240 |
| 26 | 10500 |
| 27 | 11856 |
| 28 | 13338 |
| 29 | 14924 |
| 30 | 16646 |
| 31 | 18480 |
| 32 | 20460 |
| 33 | 22560 |
| 34 | 24816 |
| 35 | 27200 |
| 36 | 29750 |
| 37 | 32436 |
| 38 | 35298 |
| 39 | 38304 |
| 40 | 41496 |
| 41 | 44840 |
| 42 | 48380 |
| 43 | 52080 |
| 44 | 55986 |
| 45 | 60060 |
| 46 | 64350 |
| 47 | 68816 |
[0,0,0,6,20,50,96,168,264,396,560,770,1020,1326, 1680,2100,2576,3128,3744,4446,5220,5880,7040,8096, 9240,10500,11856,13338,14924,16646,18480,20460, 22560,24816,27200,29750,32436,35298,38304,41496, 44840,48380,52080,55986,60060,64350,68816] |