| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 16 |
| 5 | 40 |
| 6 | 90 |
| 7 | 189 |
| 8 | 400 |
| 9 | 828 |
| 10 | 1690 |
| 11 | 3421 |
| 12 | 6864 |
| 13 | 13676 |
| 14 | 27090 |
| 15 | 53385 |
| 16 | 104736 |
| 17 | 204680 |
| 18 | 398610 |
| 19 | 773889 |
| 20 | 1498320 |
| 21 | 2893632 |
| 22 | 5575658 |
| 23 | 10721381 |
| 24 | 20577072 |
| 25 | 39424100 |
| 26 | 75412714 |
| 27 | 144040437 |
| 28 | 274743952 |
| 29 | 523380516 |
| 30 | 995841570 |
| 31 | 1892692817 |
| 32 | 3593501760 |
| 33 | 6816026448 |
| 34 | 12916524962 |
| 35 | 24455934265 |
| 36 | 46266661008 |
| 37 | 87461480600 |
| 38 | 165214492666 |
[0,1,4,9,16,40,90,189,400,828,1690,3421,6864, 13676,27090,53385,104736,204680,398610,773889, 1498320,2893632,5575658,10721381,20577072, 39424100,75412714,144040437,274743952,523380516, 995841570,1892692817,3593501760,6816026448, 12916524962,24455934265,46266661008,87461480600, 165214492666] |