N= 2(iden) 1 solutions 3 positions 7 cases N= 3(iden) 1 solutions 8 positions 19 cases N= 4(iden) 4 solutions 32 positions 91 cases N= 5(iden) 5 solutions 125 positions 299 cases N= 6(iden) 11 solutions 547 positions 1492 cases N= 7(iden) 22 solutions 2453 positions 5869 cases N= 8(iden) 57 solutions 13858 positions 33328 cases N= 9(iden) 51 solutions 85497 positions 198433 cases N=10(iden) 156 solutions 574726 positions 1339161 cases N=11(iden) 158 solutions 4268365 positions 9846356 cases N=12(iden) 566 solutions 32999210 positions 77051156 cases N=13(iden) 499 solutions 238879668 positions 556092048 cases N=14(iden) 1366 solutions 2185431858 positions 5115880399 cases N=15(iden) 3978 solutions 25455439525 positions 59727031433 cases ( 438.5h) N=16(iden) 5900 solutions 198253396876 positions 467487362728 cases (3772h)